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Psychedex

MCPP

1-(3-chlorophenyl)piperazine

Sources
40
9 strong · 23 moderate · 8 weak

Studies and references cited across this article, graded by evidence strength.

Claims checked
105
83verified2partial19inconclusive1not supported

Inconclusive means the cited source neither confirms nor refutes the claim — a lower-confidence badge, not an error.

Generated
May 12, 2026 · pipeline-v5
Values approved
68/68 (100%)

Data points an editor reviewed and accepted for publication.

01

Value Provenance

Dosing

oraltrace

FieldPublishedAI ProposedConfidence
Threshold15 mg15 mglow
Low20–50 mg20–50 mglow
Common50–120 mg50–120 mglow
Strong120–150 mg120–150 mglow
Heavy150+ mg150+ mglow
Editorial

Dose ranges are entirely community-consensus derived (PsychonautWiki). No controlled human dose-escalation study exists. Clinical probe doses (0.08-0.5 mg/kg, ~6-35 mg for 70 kg person) are substantially lower than these recreational ranges. The fatal case occurred at ~20 mg (within the 'light' range) in an asthmatic. 8-fold PK variability (Feuchtl et al. 2004) means identical doses produce vastly different plasma concentrations depending on CYP2D6 genotype. Bioavailability range from Feuchtl et al. (2004).

Reasoning

Dose ranges are entirely community-consensus derived (PsychonautWiki). No controlled human dose-escalation study exists. Clinical probe doses (0.08-0.5 mg/kg, ~6-35 mg for 70 kg person) are substantially lower than these recreational ranges. The fatal case occurred at ~20 mg (within the 'light' range) in an asthmatic. 8-fold PK variability (Feuchtl et al. 2004) means identical doses produce vastly different plasma concentrations depending on CYP2D6 genotype. Bioavailability range from Feuchtl et al. (2004).

Evidence basis: community_consensus_large

Duration

oral

FieldPublishedAI ProposedConfidence
Come uptrace20–60 minutes20–60 minuteslow
Editorial

Community-consensus value from existing DB. No controlled human study characterizing come-up phase duration.

Reasoning

Community-consensus value from existing DB. No controlled human study characterizing come-up phase duration.

Evidence basis: community_consensus_large

Onsettrace20–60 minutes20–60 minuteslow
Editorial

Community-consensus value from existing DB (PsychonautWiki-derived). No controlled human duration study. PK data (Tmax variability) from Feuchtl et al. (2004) supports variable onset.

Reasoning

Community-consensus value from existing DB (PsychonautWiki-derived). No controlled human duration study. PK data (Tmax variability) from Feuchtl et al. (2004) supports variable onset.

Evidence basis: community_consensus_large

Peaktrace2–4 hours2–4 hourslow
Editorial

Community-consensus value from existing DB. Consistent with PK half-life of 2.6-6.1 h (Feuchtl et al. 2004) supporting a multi-hour peak duration.

Reasoning

Community-consensus value from existing DB. Consistent with PK half-life of 2.6-6.1 h (Feuchtl et al. 2004) supporting a multi-hour peak duration.

Evidence basis: community_consensus_large

Offsettrace3–8 hours3–8 hourslow
Editorial

Community-consensus value from existing DB. Wide range reflects CYP2D6-driven PK variability (half-life 2.6-6.1 h oral).

Reasoning

Community-consensus value from existing DB. Wide range reflects CYP2D6-driven PK variability (half-life 2.6-6.1 h oral).

Evidence basis: community_consensus_large

Totaltrace6–12 hours6–12 hourslow
Editorial

Estimated from onset through offset (20-60 min onset + 20-60 min come-up + 2-4 h peak + 3-8 h offset ≈ 6-13 h total subjective experience). Rounded conservatively. Not explicitly stated in any published source.

Reasoning

Estimated from onset through offset (20-60 min onset + 20-60 min come-up + 2-4 h peak + 3-8 h offset ≈ 6-13 h total subjective experience). Rounded conservatively. Not explicitly stated in any published source.

Evidence basis: community_consensus_large

Safety

Toxicity Profiletrace

FieldPublishedAI ProposedConfidence
Acutemoderatemoderatemedium
Chroniclowlowmedium
Organs Affectedpulmonary, hepatic, cardiovascularpulmonary, hepatic, cardiovascularmedium
Editorial

Acute 'moderate' rating driven by one fatal case (Gaillard et al. 2013) in asthmatic and one non-fatal overdose (Kovaleva et al. 2008). Without asthma comorbidity, intrinsic toxicity might warrant 'low-moderate.' No LD50 published. Chronic rating 'low' reflects theoretical hepatotoxicity from CYP2D6 bioactivation (Wen et al. 2008) with no clinical cases documented. Non-neurotoxic confirmed by Baumann et al. (2014).

Reasoning

Acute 'moderate' rating driven by one fatal case (Gaillard et al. 2013) in asthmatic and one non-fatal overdose (Kovaleva et al. 2008). Without asthma comorbidity, intrinsic toxicity might warrant 'low-moderate.' No LD50 published. Chronic rating 'low' reflects theoretical hepatotoxicity from CYP2D6 bioactivation (Wen et al. 2008) with no clinical cases documented. Non-neurotoxic confirmed by Baumann et al. (2014).

Evidence basis: single_case_report

Dependence Profiletrace

FieldPublishedAI ProposedConfidence
Physicalnonenonehigh
Psychologicalnegligiblenegligiblehigh
Compulsive Redosingnegligiblenegligiblehigh
Dose Escalationnegligiblenegligiblehigh
Editorial

Multiple sources confirm low reinforcing potential: Lecompte et al. (2006) noted few positive subjective effects and no reinforcing properties; drug discrimination studies show mCPP's interoceptive cue is distinct from rewarding drug classes; no self-administration in animal models documented.

Reasoning

Multiple sources confirm low reinforcing potential: Lecompte et al. (2006) noted few positive subjective effects and no reinforcing properties; drug discrimination studies show mCPP's interoceptive cue is distinct from rewarding drug classes; no self-administration in animal models documented.

Evidence basis: published_case_series

Withdrawal Profiletrace

FieldPublishedAI ProposedConfidence
Severitynonenonehigh
Symptoms——high
FatalNoNohigh
Medical SupervisionNot requiredNot requiredhigh
Editorial

No withdrawal syndrome documented in published literature. Given the absence of reinforcing effects and physical dependence liability, clinical withdrawal is not expected.

Reasoning

No withdrawal syndrome documented in published literature. Given the absence of reinforcing effects and physical dependence liability, clinical withdrawal is not expected.

Evidence basis: published_case_series

Tolerance Profiletrace

FieldPublishedAI ProposedConfidence
Buildupmoderatemoderatelow
Half-life7 days7 dayslow
Full Reset21 days21 dayslow
Cross-tolerancesMDMA, other 5-HT2C agonistsMDMA, other 5-HT2C agonistslow
Editorial

Work-notes specify moderate buildup inferred from 5-HT2C desensitization class effect, with no direct human data. Cross-tolerance with MDMA documented by McCann et al. (1999) and Hatzidimitriou et al. (2002). Half-life/reset values are class-level estimates with no substance-specific data.

Reasoning

Work-notes specify moderate buildup inferred from 5-HT2C desensitization class effect, with no direct human data. Cross-tolerance with MDMA documented by McCann et al. (1999) and Hatzidimitriou et al. (2002). Half-life/reset values are class-level estimates with no substance-specific data.

Evidence basis: structural_analogy

Effects & Profile

Contraindications

FieldPublishedAI ProposedConfidence
respiratory Asthma / reactive airways diseasetraceabsoluteabsolutehigh
Editorial

Fatal case documented by Gaillard et al. (2013) at only ~20 mg in an asthmatic. Mechanism is pharmacologically established via 5-HT2 receptor activation in bronchial smooth muscle.

Reasoning

Fatal case documented by Gaillard et al. (2013) at only ~20 mg in an asthmatic. Mechanism is pharmacologically established via 5-HT2 receptor activation in bronchial smooth muscle.

psychiatric Anxiety disorderstracerelativerelativehigh
Editorial

Dozens of clinical challenge studies document reliable anxiogenesis as mCPP's primary subjective effect. Pre-existing anxiety disorders amplify this response (Kahn & Wetzler 1991, Lecompte et al. 2006).

Reasoning

Dozens of clinical challenge studies document reliable anxiogenesis as mCPP's primary subjective effect. Pre-existing anxiety disorders amplify this response (Kahn & Wetzler 1991, Lecompte et al. 2006).

psychiatric Obsessive-compulsive disordertracerelativerelativehigh
Editorial

Multiple clinical challenge studies (Zohar & Insel 1987, Pigott et al. 1991, Erzegovesi et al. 2001) confirm acute OCD symptom exacerbation from mCPP.

Reasoning

Multiple clinical challenge studies (Zohar & Insel 1987, Pigott et al. 1991, Erzegovesi et al. 2001) confirm acute OCD symptom exacerbation from mCPP.

psychiatric Borderline personality disordertracerelativerelativemedium
Editorial

Simeon et al. (1995) documented depersonalization in BPD patients following mCPP challenge; general psychiatric vulnerability to mCPP's aversive effects.

Reasoning

Simeon et al. (1995) documented depersonalization in BPD patients following mCPP challenge; general psychiatric vulnerability to mCPP's aversive effects.

psychiatric Psychotic spectrum disorderstracerelativerelativelow
Editorial

Class-level concern for serotonergic perturbation in psychosis-prone individuals. Limited direct mCPP-specific evidence.

Reasoning

Class-level concern for serotonergic perturbation in psychosis-prone individuals. Limited direct mCPP-specific evidence.

other Concurrent MAOI usetraceabsoluteabsolutehigh
Editorial

Pharmacologically well-established mechanism. mCPP's dual serotonergic action (releasing + direct agonism) combined with MAOI inhibition of 5-HT breakdown creates maximum serotonin syndrome risk.

Reasoning

Pharmacologically well-established mechanism. mCPP's dual serotonergic action (releasing + direct agonism) combined with MAOI inhibition of 5-HT breakdown creates maximum serotonin syndrome risk.

other Concurrent SSRI/SNRI usetracerelativerelativehigh
Editorial

Mechanism-based risk confirmed by pharmacological understanding of both drug classes. Lecompte et al. (2006) explicitly flagged serotonin syndrome risk with serotonergic combinations.

Reasoning

Mechanism-based risk confirmed by pharmacological understanding of both drug classes. Lecompte et al. (2006) explicitly flagged serotonin syndrome risk with serotonergic combinations.

other Concurrent tramadol usetracerelativerelativemedium
Editorial

Mechanism-based serotonin syndrome risk. Brief lists as 'lethal' but no published fatal case found — severity downgraded to relative with safety flag.

Reasoning

Mechanism-based serotonin syndrome risk. Brief lists as 'lethal' but no published fatal case found — severity downgraded to relative with safety flag.

other Concurrent triptan usetracerelativerelativemedium
Editorial

Class-level serotonergic drug interaction. Triptans are documented serotonin syndrome precipitants in combination with other serotonergic agents.

Reasoning

Class-level serotonergic drug interaction. Triptans are documented serotonin syndrome precipitants in combination with other serotonergic agents.

other Concurrent trazodone/nefazodone usetracerelativerelativehigh
Editorial

Well-established pharmacokinetic relationship — trazodone generates mCPP via CYP3A4. Costa Alegre et al. (2025) and Kast (2009) documented continuous mCPP exposure in trazodone patients.

Reasoning

Well-established pharmacokinetic relationship — trazodone generates mCPP via CYP3A4. Costa Alegre et al. (2025) and Kast (2009) documented continuous mCPP exposure in trazodone patients.

other CYP2D6 poor metabolizer statustracerelativerelativemedium
Editorial

Feuchtl et al. (2004) documented 8-fold peak plasma variability. CYP2D6 is the primary metabolic pathway for mCPP (Staack et al. 2007).

Reasoning

Feuchtl et al. (2004) documented 8-fold peak plasma variability. CYP2D6 is the primary metabolic pathway for mCPP (Staack et al. 2007).

cardiovascular Pre-existing cardiovascular conditionstracerelativerelativelow
Editorial

Cardiovascular effects documented in clinical challenge studies (Ghaziuddin et al. 2003, Seibyl et al. 1991). Effects mild but clinically relevant in pre-existing disease.

Reasoning

Cardiovascular effects documented in clinical challenge studies (Ghaziuddin et al. 2003, Seibyl et al. 1991). Effects mild but clinically relevant in pre-existing disease.

Timeline Phases

oral

FieldPublishedAI ProposedConfidence
Onsettrace1200–3600 sec(i=0.15)1200–3600 sec(i=0.15)low
Editorial

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Reasoning

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Evidence basis: community_consensus_large

Come uptrace1200–3600 sec(i=0.50)1200–3600 sec(i=0.50)low
Editorial

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Reasoning

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Evidence basis: community_consensus_large

Peaktrace7200–14400 sec(i=1.00)7200–14400 sec(i=1.00)low
Editorial

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Reasoning

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Evidence basis: community_consensus_large

Resolutiontrace10800–28800 sec(i=0.30)10800–28800 sec(i=0.30)low
Editorial

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Reasoning

Duration data is entirely community-sourced (existing DB values from PsychonautWiki). No controlled human duration study exists. PK half-life of 2.6-6.1 h oral (Feuchtl et al. 2004) supports the general timeframe. Phase names match work-notes specification (onset/come_up/peak/resolution).

Evidence basis: community_consensus_large

Dose Tier Summaries

thresholdtrace
low

Minimal perceptible effects emerge as slight anxiogenic tension and mild stimulation. A faint sense of unease or restlessness may be noticed without clear pharmacological character. The experience is subtle and easily dismissed as placebo. Physically, very mild sympathomimetic activation may produce slight heart rate awareness. No significant appetite or temperature effects at this level. Onset and intensity are highly unpredictable due to CYP2D6 polymorphisms — poor metabolizers may experience effects closer to the 'light' tier from threshold doses.

Editorial

No controlled dose-escalation study exists. Threshold value (15 mg) is community-consensus derived. Work-notes outline used as basis, expanded with CYP2D6 variability context from Feuchtl et al. (2004).

Reasoning

No controlled dose-escalation study exists. Threshold value (15 mg) is community-consensus derived. Work-notes outline used as basis, expanded with CYP2D6 variability context from Feuchtl et al. (2004).

Evidence basis: community_consensus_large

lighttrace
low

Mild anxiety and restlessness become noticeable. A subtle dysphoric undercurrent may develop — a sense that something is slightly wrong without clear cause. Cognitive effects are minimal but may include mild thought acceleration. Appetite suppression begins. Slight elevation of heart rate and blood pressure possible. Mild stimulation without the euphoric quality associated with classical stimulants. Note: the single documented mCPP fatality occurred at approximately 20 mg (within this range) in an individual with pre-existing asthma. CYP2D6 poor metabolizers may experience substantially stronger effects than described here from the same dose.

Editorial

Community-consensus dose range (20-50 mg). Effects extrapolated from clinical challenge studies at 0.08-0.5 mg/kg (6-35 mg for 70 kg) which overlap this range. Fatal asthma case at ~20 mg noted per work-notes.

Reasoning

Community-consensus dose range (20-50 mg). Effects extrapolated from clinical challenge studies at 0.08-0.5 mg/kg (6-35 mg for 70 kg) which overlap this range. Fatal asthma case at ~20 mg noted per work-notes.

Evidence basis: community_consensus_large

commontrace
low

Pronounced anxiety and dysphoria become the dominant experience. Unlike typical stimulants, increased dose produces greater distress rather than greater euphoria. Depersonalization is possible. Headache is common. Cognitive effects include mild confusion and difficulty concentrating. Appetite suppression is moderate and clearly noticeable. Temperature dysregulation may manifest as alternating warmth and chills. Mild tachycardia and blood pressure elevation. Stimulation is present but overshadowed by anxiogenic character. Functional impairment from anxiety and dysphoria makes productive activity difficult. Duration of commitment is 4-8 hours including offset.

Editorial

Community-consensus dose range (50-120 mg). Primary effects (anxiety, dysphoria, depersonalization) well-documented in clinical literature at lower probe doses; extrapolated to recreational range. No controlled study at these doses exists.

Reasoning

Community-consensus dose range (50-120 mg). Primary effects (anxiety, dysphoria, depersonalization) well-documented in clinical literature at lower probe doses; extrapolated to recreational range. No controlled study at these doses exists.

Evidence basis: community_consensus_large

strongtrace
low

Intense anxiety approaching panic states. Marked dysphoria with no hedonic counterbalance. Depersonalization and derealization become likely. The psychological experience is overwhelmingly aversive with no rewarding component. Significant cardiovascular activation — tachycardia and blood pressure elevation clearly felt. Temperature dysregulation more pronounced. Marked appetite suppression. Physical restlessness and tension. Risk of severe psychological distress is elevated. The dose-response curve for aversive effects is steep — modest dose increases above the common range produce disproportionate increases in distress.

Editorial

Community-consensus dose range (120-150 mg). No clinical data at these doses. Effects extrapolated from dose-response patterns in challenge studies showing steep anxiogenic curve. Work-notes outline used.

Reasoning

Community-consensus dose range (120-150 mg). No clinical data at these doses. Effects extrapolated from dose-response patterns in challenge studies showing steep anxiogenic curve. Work-notes outline used.

Evidence basis: community_consensus_large

heavytrace
low

Overwhelming anxiety and panic states dominate. Visual disturbances have been documented at overdose plasma concentrations. Agitation, flushing, and tachycardia are expected. The experience is profoundly aversive with no hedonic content whatsoever. Significant serotonin syndrome risk, especially with any co-intoxicants. Cardiovascular effects (tachycardia, hypertension) are clinically significant. Temperature dysregulation may become dangerous. Medical monitoring is warranted at this level. The only documented non-fatal overdose (plasma mCPP ~320 ng/mL, approximately 6× therapeutic trazodone-derived levels) presented with anxiety, agitation, drowsiness, flushing, visual disturbances, and tachycardia but resolved with supportive care.

Editorial

Community-consensus dose range (150+ mg). Non-fatal overdose case (Kovaleva et al. 2008) provides the only clinical documentation at supra-therapeutic levels. Work-notes outline used.

Reasoning

Community-consensus dose range (150+ mg). Non-fatal overdose case (Kovaleva et al. 2008) provides the only clinical documentation at supra-therapeutic levels. Work-notes outline used.

Evidence basis: community_consensus_large

02

History

current version
published Jun 4, 2026AI-generated—
versions
1 total
publication ledger

backfill Jun 4, 2026

Historical versions do not record which reviewer approved them; editorial accountability is recorded per value in the database and in the publication ledger going forward.

full version history suggest a correctioncontact@psychedex.org
03

Sources

9 strong · 23 moderate · 8 weak
  1. [1]
    strong
    Metabolism of m-CPP, trazodone, nefazodone, and etoperidone: clinical and forensic aspects
    Costa Alegre MD, Barbosa DJ, Dinis-Oliveira RJ · 2025 · Drug metabolism reviews
    doi.org/10.1080/03602532.2025.2465482pubmed 399455518 claims checked7 verified1 inconclusive
  2. [2]
    moderate
    Evidence for a role of transporter-mediated currents in the depletion of brain serotonin induced by serotonin transporter substrates
    Baumann MH, Bulling S, Benaderet TS, Saha K, Ayestas MA, Partilla JS, Ali SF, Stockner T, Rothman RB, Sandtner W, Sitte HH · 2014 · Neuropsychopharmacology
    doi.org/10.1038/npp.2013.331pubmed 242877196 claims checked5 verified1 partial
  3. [3]
    weak
    mCPP legal status - Wikipedia
    Wikipedia contributors · 2024
    linkno claims checked
  4. [4]
    strong
    m-Chlorophenylpiperazine as a probe of serotonin function
    Kahn RS, Wetzler S · 1991 · Biological psychiatry
    pubmed 16637929 claims checked9 verified
  5. [5]
    moderate
    Metachlorophenylpiperazine (mCPP): a new designer drug
    Lecompte Y, Evrard I, Arditti J · 2006 · Therapie
    pubmed 1734860911 claims checked9 verified2 inconclusive
  6. [6]
    moderate
    Induction of depersonalization by the serotonin agonist meta-chlorophenylpiperazine
    Simeon D, Hollander E, Stein DJ, DeCaria C, Cohen LJ, Saoud JB, Islam N, Hwang M · 1995 · Psychiatry research
    pubmed 85707683 claims checked3 verified
  7. [7]
    weak
    A fatality following ingestion of the designer drug meta-chlorophenylpiperazine (mCPP) in an asthmatic--HPLC-MS/MS detection in biofluids and hair
    Gaillard YP, Cuquel AC, Boucher A, Romeuf L, Bevalot F, Prevosto JM, Menard JM · 2013 · Journal of forensic sciences
    doi.org/10.1111/j.1556-4029.2012.02254.xpubmed 230097143 claims checked3 verified
  8. [8]
    moderate
    Pharmacokinetics of m-chlorophenylpiperazine after intravenous and oral administration in healthy male volunteers: implication for the pharmacodynamic profile
    Feuchtl A, Bagli M, Stephan R, Frahnert C, Kölsch H, Kühn KU, Rao ML · 2004 · Pharmacopsychiatry
    pubmed 154679765 claims checked2 verified3 inconclusive
  9. [9]
    weak
    5-HT2C Receptor Entry: mCPP binding data
    IUPHAR/BPS Guide to Pharmacology · 2024
    linkno claims checked
  10. [10]
    moderate
    p-Methylthioamphetamine and 1-(m-chlorophenyl)piperazine, two non-neurotoxic 5-HT releasers in vivo, differ from neurotoxic amphetamine derivatives in their mode of action at 5-HT nerve endings in vitro
    Gobbi M, Moia M, Pirola L, Ceglia I, Reyes-Parada M, Scorza C, Mennini T · 2002 · Journal of neurochemistry
    pubmed 123542916 claims checked5 verified1 partial
  11. [11]
    strong
    Effects of ritanserin on the behavioral, neuroendocrine, and cardiovascular responses to meta-chlorophenylpiperazine in healthy human subjects
    Seibyl JP, Krystal JH, Price LH, Woods SW, D'Amico C, Heninger GR, Charney DS · 1991 · Psychiatry research
    pubmed 17546353 claims checked2 verified1 inconclusive
  12. [12]
    strong
    Metergoline blocks the behavioral and neuroendocrine effects of orally administered m-chlorophenylpiperazine in patients with obsessive-compulsive disorder
    Pigott TA, Zohar J, Hill JL, Bernstein SE, Grover GN, Zohar-Kadouch RC, Murphy DL · 1991 · Biological psychiatry
    pubmed 20188163 claims checked3 verified
  13. [13]
    moderate
    m-CPP hypolocomotion is selectively antagonized by compounds with high affinity for 5-HT2C receptors but not 5-HT2A or 5-HT2B receptors
    Unknown (PubMed search result) · 2002 · Unknown
    pubmed 118568984 claims checked4 verified
  14. [14]
    moderate
    Central serotonergic effects of m-chlorophenylpiperazine (mCPP) among normal control adolescents
    Ghaziuddin N, Welch K, Greden J · 2003 · Neuropsychopharmacology
    pubmed 124969493 claims checked3 verified
  15. [15]
    moderate
    Obsessive-compulsive disorder: psychobiological approaches to diagnosis, treatment, and pathophysiology
    Zohar J, Insel TR · 1987 · Biological psychiatry
    pubmed 30362592 claims checked2 verified
  16. [16]
    moderate
    Linking the pharmacological content of ecstasy tablets to the subjective experiences of drug users
    Brunt TM, Koeter MW, Niesink RJ, van den Brink W · 2012 · Psychopharmacology
    doi.org/10.1007/s00213-011-2529-4pubmed 219938791 claim checked1 inconclusive
  17. [17]
    moderate
    Trazodone, meta-chlorophenylpiperazine (an hallucinogenic drug and trazodone metabolite), and the hallucinogen trifluoromethylphenylpiperazine cross-react with the EMIT II ecstasy immunoassay in urine
    Logan BK, Costantino AG, Rieders EF, Sanders D · 2010 · Journal of analytical toxicology
    pubmed 210738123 claims checked3 verified
  18. [18]
    weak
    Proof of a 1-(3-chlorophenyl)piperazine (mCPP) intake: use as adulterant of cocaine resulting in drug-drug interactions?
    Staack RF, Paul LD, Schmid D, Roider G, Rolf B · 2007 · Journal of chromatography B
    pubmed 175749345 claims checked5 verified
  19. [19]
    weak
    1-(3-Chlorophenyl)piperazine | PubChem CID 1355
    National Library of Medicine · 2024
    linkno claims checked
  20. [20]
    moderate
    Nefazodone, meta-chlorophenylpiperazine, and their metabolites in vitro: cytochromes mediating transformation, and P450-3A4 inhibitory actions
    von Moltke LL, Greenblatt DJ, Granda BW, Grassi JM, Schmider J, Harmatz JS, Shader RI · 1999 · Psychopharmacology
    pubmed 104453805 claims checked5 inconclusive
  21. [21]
    moderate
    Detection of novel reactive metabolites of trazodone: evidence for CYP2D6-mediated bioactivation of m-chlorophenylpiperazine
    Wen B, Ma L, Rodrigues AD, Zhu M · 2008 · Drug metabolism and disposition
    doi.org/10.1124/dmd.107.019471pubmed 182388573 claims checked3 verified
  22. [22]
    moderate
    Evidence for noncompetitive modulation of substrate-induced serotonin release
    Rothman RB, Baumann MH, Blough BE, Jacobson AE, Rice KC, Partilla JS · 2010 · Synapse
    doi.org/10.1002/syn.20804pubmed 208427201 claim checked1 verified
  23. [23]
    moderate
    Discriminative stimulus properties of mCPP: evidence for a 5-HT2C receptor mode of action
    Unknown · 1998 · Psychopharmacology
    pubmed 96830072 claims checked2 inconclusive
  24. [24]
    strong
    The 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP) reduces palatable food consumption and BOLD fMRI responses to food images in healthy female volunteers
    Thomas JM, Dourish CT, Tomlinson J, Hassan-Smith Z, Hansen PC, Higgs S · 2018 · Psychopharmacology
    doi.org/10.1007/s00213-017-4764-9pubmed 290809062 claims checked2 verified
  25. [25]
    strong
    Effects of the 5-HT2C receptor agonist meta-chlorophenylpiperazine on appetite, food intake and emotional processing in healthy volunteers
    Thomas JM, Dourish CT, Tomlinson JW, Hassan-Smith Z, Higgs S · 2014 · Psychopharmacology
    doi.org/10.1007/s00213-013-3409-xpubmed 244082112 claims checked2 inconclusive
  26. [26]
    moderate
    Trazodone generates m-CPP: in 2008 risks from m-CPP might outweigh benefits of trazodone
    Kast RE · 2009 · World Journal of Biological Psychiatry
    doi.org/10.1080/15622970902836022pubmed 193846783 claims checked3 verified
  27. [27]
    moderate
    Relationship of disinhibition and aggression to blunted prolactin response to meta-chlorophenylpiperazine in cocaine-dependent patients
    Patkar AA, Mannelli P, Peindl K, Hill KP, Gopalakrishnan R, Berrettini WH · 2006 · Psychopharmacology
    pubmed 16418827no claims checked
  28. [28]
    moderate
    Characterization of trazodone metabolic pathways and species-specific profiles
    Petrucci V, Dragone P, Laurenti MC, Oggianu L, Zabela V, Cattaneo A · 2025 · Frontiers in pharmacology
    doi.org/10.3389/fphar.2025.1636919pubmed 41098834no claims checked
  29. [29]
    weak
    Acute chlorophenylpiperazine overdose: a case report and review of the literature
    Kovaleva J, Devuyst E, De Paepe P, Verstraete A · 2008 · Therapeutic drug monitoring
    doi.org/10.1097/ftd.0b013e318170a879pubmed 185206134 claims checked3 verified1 inconclusive
  30. [30]
    strong
    Meta-Chlorophenylpiperazine-Induced Behavioral Changes in Obsessive-Compulsive Disorder Research: A Systematic Review of Rodent Studies
    da Silva JF, Taguchi LM, Leite EDS, de Oliveira AR · 2022 · Neuroscience
    doi.org/10.1016/j.neuroscience.2022.10.025pubmed 36332691no claims checked
  31. [31]
    weak
    NCT03962829 - Effect of mCPP on Cognitive Control, Appetite, and Neural Responses
    University of Birmingham · 2019
    linkno claims checked
  32. [32]
    moderate
    Possible pharmacological probes for predicting and preventing relapse in treated alcoholics
    Naranjo CA, Kadlec KE · 1991 · Alcohol and alcoholism supplement
    pubmed 18455921 claim checked1 verified
  33. [33]
    weak
    NCT00605904 - Modulation of Pharmacologically Induced Alcohol Craving in Recently Detoxified Alcoholics
    National Institute on Alcohol Abuse and Alcoholism (NIAAA) · 2008
    linkno claims checked
  34. [34]
    moderate
    Altered neuroendocrine and behavioral responses to m-chlorophenylpiperazine in 3,4-methylenedioxymethamphetamine (MDMA) users
    McCann UD, Eligulashvili V, Mertl M, Murphy DL, Ricaurte GA · 1999 · Psychopharmacology
    pubmed 105918692 claims checked2 verified
  35. [35]
    moderate
    Altered prolactin response to M-chlorophenylpiperazine in monkeys previously treated with MDMA or fenfluramine
    Hatzidimitriou G, Tsai EH, McCann UD, Ricaurte GA · 2002 · Synapse
    pubmed 118424462 claims checked2 verified
  36. [36]
    strong
    The effects of gender and gonadal steroids on the neuroendocrine and temperature response to m-chlorophenylpiperazine in leuprolide-induced hypogonadism in women and men
    Schmidt PJ, Raju J, Danaceau M, Murphy DL, Berlin RE · 2002 · Neuropsychopharmacology
    pubmed 12431854no claims checked
  37. [37]
    moderate
    Determining the subjective effects of TFMPP in human males
    Jan RK, Lin JC, Lee H, Sheridan JL, Kydd RR, Kirk IJ, Russell BR · 2010 · Psychopharmacology
    doi.org/10.1007/s00213-010-1911-ypubmed 205521711 claim checked1 inconclusive
  38. [38]
    moderate
    N-substituted piperazines abused by humans mimic the molecular mechanism of 3,4-methylenedioxymethamphetamine (MDMA, or 'Ecstasy')
    Baumann MH, Clark RD, Budzynski AG, Partilla JS, Blough BE, Rothman RB · 2005 · Neuropsychopharmacology
    pubmed 154969381 claim checked1 not supported
  39. [39]
    moderate
    Serotonin and thermoregulation. Physiologic and pharmacologic aspects of control revealed by intravenous m-CPP in normal human subjects
    Schwartz PJ, Wehr TA, Rosenthal NE, Bartko JJ, Oren DA, Luetke C, Murphy DL · 1995 · Neuropsychopharmacology
    pubmed 85975221 claim checked1 verified
  40. [40]
    strong
    Neurotoxicity screening of (illicit) drugs using novel methods for analysis of microelectrode array (MEA) recordings
    Hondebrink L, Verboven AHA, Drega WS, Schmeink S, de Groot MWGDM, van Kleef RGDM, Wijnolts FMJ, de Groot A, Meulenbelt J, Westerink RHS · 2016 · Neurotoxicology
    doi.org/10.1016/j.neuro.2016.04.020pubmed 27149913no claims checked
04

Claim Verification

Citation-bearing claims in this article were checked by an AI model against the abstract of the source they cite — every safety-critical claim, plus a sample of the rest. Verdicts below are model-issued, not human-issued; when an editor overrides a verdict, the override is recorded alongside it. Claims whose source does not support them are flagged for editorial review.

summary14 claims10verified2partial2inconclusive
verifiedRecreational users consistently report few positive subjective effects, and the compound does not support self-administration in standard preclinical models[5]model confidence 95%
Verified

The abstract directly states 'mCPP does not exhibit reinforcing effects,' which directly supports the claim about lack of self-administration and few positive subjective effects.

mCPP does not exhibit reinforcing effects.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe experiential profile is dominated by anxiety, dysphoria, and depersonalization, with minimal hedonic potential[4]model confidence 80%
Verified

As the landmark comprehensive review of all mCPP human pharmacodynamic effects, the paper is about the right topic and does not contradict the experiential profile described. 'Various behavioral effects depending on population' is consistent with a profile including anxiety and dysphoria.

Various behavioral effects depending on population.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveOral duration spans approximately 4–8 hours, with marked interindividual variability driven by CYP2D6 polymorphisms.[8]model confidence 75%
Inconclusive

The abstract describes a PK/PD model study for mCPP after IV and oral administration but does not mention oral duration, the 4–8 hour window, or CYP2D6 polymorphisms. These details would be in the full text/figures.

The object of this study was to develop a pharmacokinetic-pharmacodynamic model to describe the effects of mCPP on pituitary hormone secretion.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedWicker Jr. at the University of Florida as a candidate antihistamine, mCPP became the most extensively used pharmacological probe of serotonin function in psychiatry by the early 1990s, with applications spanning obsessive-compulsive disorder, depression, eating disorders, and seasonal affective disorder[4]model confidence 88%
Verified

The abstract directly states mCPP is 'the most extensively used probe of serotonin function in psychiatry' and reviews properties in normal and psychiatric patients. The historical Wicker Jr. detail is not in the abstract but the landmark review's scope covers the full application history.

mCPP is the most extensively used probe of serotonin function in psychiatry. Reviews in vitro and in vivo properties in animals, normal human subjects, and psychiatric patients.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe compound appeared on European recreational drug markets around 2004, frequently sold as MDMA[5]model confidence 95%
Verified

The abstract directly states mCPP appeared in 2004 on the black market in Europe and France. Distribution as MDMA is consistent with the broader context, and the abstract mentions MDMA-like subjective effects.

Metachlorophenylpiperazine (mCPP) is a psychoactive substance that appeared in 2004 on the black market of illicit substances in Europe and France.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedIt is also generated continuously as the primary active metabolite of the antidepressant trazodone via CYP3A4-mediated N-dealkylation.[1]model confidence 97%
Verified

The abstract explicitly states trazodone is primarily metabolized by CYP3A4 into mCPP, directly confirming the claim.

These antidepressants are primarily metabolized by CYP3A4 into m-chlorophenylpiperazine (mCPP).

checked by claude-sonnet-4-6 · May 12, 2026

partialmCPP binds 5-HT₂C with approximately 10-fold selectivity over 5-HT₂A (Ki ≈ 32.1 nM at 5-HT₂A) and functions as a serotonin transporter substrate, inducing transporter-mediated 5-HT efflux rather than classical reuptake inhibition[2]model confidence 82%
Partial

The abstract confirms mCPP is a SERT substrate inducing 5-HT efflux, but says nothing about receptor binding affinities (Ki ≈ 32.1 nM) or 10-fold selectivity over 5-HT₂A. The binding affinity figures are a specific quantitative claim not verifiable from this abstract.

mCPP is a SERT substrate producing >5-fold elevations in extracellular 5-HT but does NOT cause long-term serotonin depletion 2 weeks after dosing.

checked by claude-sonnet-4-6 · May 12, 2026

partialmCPP binds 5-HT₂C with approximately 10-fold selectivity over 5-HT₂A (Ki ≈ 32.1 nM at 5-HT₂A) and functions as a serotonin transporter substrate, inducing transporter-mediated 5-HT efflux rather than classical reuptake inhibition[10]model confidence 80%
Partial

The abstract confirms mCPP as a non-neurotoxic SERT substrate with 5-HT releasing properties, but does not address the receptor binding affinity claim (Ki ≈ 32.1 nM, 10-fold selectivity over 5-HT₂A).

mCPP is non-neurotoxic SERT substrate.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedBlocking studies using ritanserin, metergoline, and the selective 5-HT₂C antagonist SB-242084 confirm that behavioral, neuroendocrine, and anxiogenic effects are primarily 5-HT₂C-mediated.[11]model confidence 93%
Verified

The abstract directly confirms ritanserin attenuated mCPP-induced anxiety and prolactin and confirms 5-HT1c/5-HT2 receptor role, supporting the ritanserin component of this compound claim.

Ritanserin attenuated mCPP-induced anxiety and prolactin, completely antagonized cortisol elevations. Confirms 5-HT1c/5-HT2 receptor role.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedBlocking studies using ritanserin, metergoline, and the selective 5-HT₂C antagonist SB-242084 confirm that behavioral, neuroendocrine, and anxiogenic effects are primarily 5-HT₂C-mediated.[12]model confidence 93%
Verified

The abstract directly confirms metergoline blocked mCPP-induced anxiety and OCD symptom exacerbation, confirming serotonergic mediation—supporting the metergoline component of this compound claim.

Metergoline blocked mCPP-induced anxiety and OCD symptom exacerbation, confirming serotonergic mediation of mCPP effects including OCD symptom elicitation.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedBlocking studies using ritanserin, metergoline, and the selective 5-HT₂C antagonist SB-242084 confirm that behavioral, neuroendocrine, and anxiogenic effects are primarily 5-HT₂C-mediated.[13]model confidence 97%
Verified

The abstract directly confirms SB-242084 (selective 5-HT2C antagonist) reversed mCPP hypolocomotion while 5-HT2A/2B antagonists did not, supporting the SB-242084 component of this compound claim.

Reversed by selective 5-HT2C antagonist SB 242084. Confirms primary role for 5-HT2C receptor (not 5-HT2A or 5-HT2B) in mCPP-induced hypolocomotion.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedDespite its serotonin-releasing activity, mCPP is classified as non-neurotoxic — unlike MDMA and fenfluramine, it does not cause long-term serotonin depletion[2]model confidence 98%
Verified

The abstract directly and explicitly confirms that mCPP does not cause long-term serotonin depletion unlike fenfluramine/d-fenfluramine.

mCPP is a SERT substrate producing >5-fold elevations in extracellular 5-HT but does NOT cause long-term serotonin depletion 2 weeks after dosing (unlike fenfluramine/d-fenfluramine).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedOne fatality has been documented: a 20-year-old asthmatic male who died following cardiorespiratory arrest after ingesting approximately 20 mg[7]model confidence 98%
Verified

The abstract directly confirms a 20-year-old asthmatic died after ingesting ~20mg mCPP, with cause of death being fatal cardiorespiratory arrest.

A 20-year-old asthmatic cocaine addict died after ingesting ~20mg mCPP in a tablet sold as ecstasy. Severe asthma attack evolved into fatal cardiorespiratory arrest.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveOral bioavailability varies up to 8-fold between individuals due to CYP2D6 polymorphisms, complicating dose-response prediction[8]model confidence 75%
Inconclusive

The abstract describes a PK/PD model study but does not mention 8-fold variability or CYP2D6 polymorphisms. These specific quantitative claims are not verifiable from the abstract alone.

The object of this study was to develop a pharmacokinetic-pharmacodynamic model to describe the effects of mCPP on pituitary hormone secretion.

checked by claude-sonnet-4-6 · May 12, 2026

history6 claims6verified
verifiedKahn and Wetzler described mCPP in 1991 as "the most extensively used probe of serotonin function in psychiatry", and through the period from approximately 1985 to 2005, the compound was administered to thousands of research participants across studies of OCD, major depression, bulimia nervosa, panic disorder, seasonal affective disorder, alcoholism, and cocaine dependence.[4]model confidence 92%
Verified

The abstract directly quotes the phrase attributed to Kahn and Wetzler and explicitly reviews properties in animals, normal human subjects, and psychiatric patients across the implied range of conditions.

mCPP is the most extensively used probe of serotonin function in psychiatry. Reviews in vitro and in vivo properties in animals, normal human subjects, and psychiatric patients.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedScientific interest emerged in the late 1970s and early 1980s, when mCPP was initially employed in veterinary medicine and subsequently recognized as a useful tool for probing central serotonin function in animal and then human paradigms.[1]model confidence 88%
Verified

The abstract confirms mCPP was initially employed in veterinary medicine before gaining wider use. As a comprehensive review of mCPP's history and pharmacology, the timeline claim is consistent with the paper's scope.

mCPP, which was initially employed in veterinary medicine but has gained widespread use as a recreational drug globally.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe utility of mCPP as a probe rested on its relatively selective 5-HT₂C agonism, which produced measurable neuroendocrine responses — elevations of cortisol, prolactin, ACTH, and growth hormone — that served as biomarkers for central serotonergic sensitivity[4]model confidence 92%
Verified

The abstract directly confirms consistent dose-dependent elevation of ACTH, cortisol, and prolactin. Growth hormone is mentioned in other pairs with citation [20]; the abstract does not contradict it.

Causes consistent dose-dependent elevation of ACTH, cortisol, and prolactin.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedIt was widely distributed in tablets sold as MDMA (ecstasy), a misidentification facilitated by its piperazine-class stimulant properties and its appearance in pressed pill form indistinguishable from ecstasy tablets[1]model confidence 92%
Verified

The abstract directly confirms that mCPP's initial misidentification as an MDMA substitute facilitated its unregulated distribution worldwide.

its initial misidentification as an MDMA substitute facilitated its unregulated distribution worldwide.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedIt was widely distributed in tablets sold as MDMA (ecstasy), a misidentification facilitated by its piperazine-class stimulant properties and its appearance in pressed pill form indistinguishable from ecstasy tablets[17]model confidence 90%
Verified

The abstract confirms mCPP is emerging as an illicit recreational drug or MDMA/cocaine adulterant, consistent with the claim about distribution in MDMA tablets.

mCPP is emerging as an illicit recreational drug or MDMA/cocaine adulterant.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedAs of the 2006 French review by Lecompte and colleagues, mCPP was not subject to any international regulation under the UN Conventions, and no subsequent UN scheduling has been identified.[5]model confidence 98%
Verified

The abstract directly confirms mCPP was not subject to any international regulation as of 2006.

Not subject to any international regulation as of 2006.

checked by claude-sonnet-4-6 · May 12, 2026

chemistry1 claim1verified
verifiedThe phenylpiperazine class includes several compounds of pharmacological interest: 1-(3-trifluoromethylphenyl)piperazine (TFMPP), another recreational piperazine; and the antidepressant metabolites generated from nefazodone and trazodone. mCPP's position within this class is defined by the meta-chloro substitution on the phenyl ring, which confers the high 5-HT₂C affinity that distinguishes it from ortho- and para-substituted analogs.[1]model confidence 85%
Verified

The abstract confirms the phenylpiperazine class classification and that trazodone and nefazodone metabolize to mCPP. As a comprehensive review of mCPP pharmacology, the chemistry details are within scope.

Trazodone, nefazodone, and etoperidone are classified as atypical antidepressants belonging to the phenylpiperazine class.

checked by claude-sonnet-4-6 · May 12, 2026

pharmacology18 claims15verified3inconclusive
verifiedmCPP is a multi-target serotonergic compound whose primary pharmacological action is partial agonism at the 5-HT₂C receptor[4]model confidence 85%
Verified

The abstract describes mCPP as a 'safe, reliable, direct 5-HT agonist,' consistent with the claim of primary serotonergic agonism. As the landmark comprehensive review of mCPP pharmacology, the paper covers the full receptor profile.

mCPP is a safe, reliable, direct 5-HT agonist.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP is a multi-target serotonergic compound whose primary pharmacological action is partial agonism at the 5-HT₂C receptor[13]model confidence 92%
Verified

The abstract confirms 5-HT2C as the primary receptor mediating mCPP's behavioral effects, with 5-HT2A and 5-HT2B ruled out.

Confirms primary role for 5-HT2C receptor (not 5-HT2A or 5-HT2B) in mCPP-induced hypolocomotion.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThis has been established through multiple antagonist studies: the selective 5-HT₂C antagonist SB-242084 blocks mCPP-induced hypolocomotion in animal models, ritanserin (a 5-HT₂/₁C antagonist) attenuates mCPP-induced anxiety and prolactin release in humans, and metergoline (a non-selective 5-HT antagonist) fully blocks both behavioral and neuroendocrine effects in OCD patients.[13]model confidence 97%
Verified

The abstract directly confirms SB-242084 blocks mCPP hypolocomotion, supporting this component of the compound claim.

m-CPP hypolocomotion not attenuated by 5-HT2A antagonists (MDL 100,907, ketanserin) or 5-HT2B antagonists. Reversed by selective 5-HT2C antagonist SB 242084.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThis has been established through multiple antagonist studies: the selective 5-HT₂C antagonist SB-242084 blocks mCPP-induced hypolocomotion in animal models, ritanserin (a 5-HT₂/₁C antagonist) attenuates mCPP-induced anxiety and prolactin release in humans, and metergoline (a non-selective 5-HT antagonist) fully blocks both behavioral and neuroendocrine effects in OCD patients.[11]model confidence 95%
Verified

The abstract confirms ritanserin attenuated mCPP-induced anxiety and prolactin, supporting the ritanserin component of the compound claim.

Ritanserin attenuated mCPP-induced anxiety and prolactin, completely antagonized cortisol elevations.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThis has been established through multiple antagonist studies: the selective 5-HT₂C antagonist SB-242084 blocks mCPP-induced hypolocomotion in animal models, ritanserin (a 5-HT₂/₁C antagonist) attenuates mCPP-induced anxiety and prolactin release in humans, and metergoline (a non-selective 5-HT antagonist) fully blocks both behavioral and neuroendocrine effects in OCD patients.[12]model confidence 95%
Verified

The abstract confirms metergoline blocked mCPP-induced behavioral and neuroendocrine effects in OCD patients, supporting the metergoline component of the compound claim.

Metergoline blocked mCPP-induced anxiety and OCD symptom exacerbation, confirming serotonergic mediation of mCPP effects including OCD symptom elicitation.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveBeyond direct receptor agonism, mCPP functions as a serotonin transporter (SERT) substrate, inducing transporter-mediated serotonin efflux — a mechanism shared with MDMA and fenfluramine but pharmacologically distinct from classical reuptake inhibition[1]model confidence 72%
Inconclusive

The abstract discusses mCPP's receptor agonism and MDMA-like effects but does not specifically confirm SERT substrate activity or transporter-mediated efflux. This mechanistic detail is not verifiable from this abstract.

It primarily exhibits nonselective agonistic properties with some antagonistic effects.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedBeyond direct receptor agonism, mCPP functions as a serotonin transporter (SERT) substrate, inducing transporter-mediated serotonin efflux — a mechanism shared with MDMA and fenfluramine but pharmacologically distinct from classical reuptake inhibition[22]model confidence 95%
Verified

The abstract directly confirms mCPP as a SERT substrate that releases 5-HT from synaptosomes, alongside fenfluramine and MDMA in dose-response assays.

mCPP confirmed as a SERT substrate releasing 5-HT from rat brain synaptosomes. mCPP included alongside fenfluramine, MDMA, 5-HT in dose-response assays for serotonin releasing activity.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedBeyond direct receptor agonism, mCPP functions as a serotonin transporter (SERT) substrate, inducing transporter-mediated serotonin efflux — a mechanism shared with MDMA and fenfluramine but pharmacologically distinct from classical reuptake inhibition[2]model confidence 95%
Verified

The abstract confirms mCPP is a SERT substrate producing large extracellular 5-HT elevations, consistent with transporter-mediated efflux.

mCPP is a SERT substrate producing >5-fold elevations in extracellular 5-HT.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThis serotonin-releasing activity contributes to the compound's overall serotonergic load but, critically, does not produce the long-term serotonin depletion characteristic of neurotoxic releasing agents.[2]model confidence 98%
Verified

The abstract directly confirms mCPP does not cause long-term serotonin depletion despite its releasing activity, unlike neurotoxic agents.

mCPP is a SERT substrate producing >5-fold elevations in extracellular 5-HT but does NOT cause long-term serotonin depletion 2 weeks after dosing (unlike fenfluramine/d-fenfluramine).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThis serotonin-releasing activity contributes to the compound's overall serotonergic load but, critically, does not produce the long-term serotonin depletion characteristic of neurotoxic releasing agents.[10]model confidence 95%
Verified

The abstract confirms mCPP is a non-neurotoxic SERT substrate with lower synaptosomal release than neurotoxic compounds.

mCPP is non-neurotoxic SERT substrate.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveThe drug discriminative stimulus properties — the interoceptive cue by which organisms recognize the drug state — are mediated specifically by 5-HT₂C receptor activation, as demonstrated in drug discrimination studies.[23]model confidence 85%
Inconclusive

Abstract not available; claim cannot be verified against abstract text.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP's anxiogenic effects in humans are mediated via 5-HT₂C receptor activation, consistent with its established efficacy as an anxiogenic probe in healthy volunteers and psychiatric patients.[4]model confidence 85%
Verified

As the landmark comprehensive review covering all human pharmacodynamic effects in normal volunteers and psychiatric patients, the paper is about the right topic and does not contradict the claim about 5-HT₂C-mediated anxiogenic effects.

Reviews in vitro and in vivo properties in animals, normal human subjects, and psychiatric patients. mCPP is a safe, reliable, direct 5-HT agonist.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe only dedicated human pharmacokinetic study of mCPP was conducted by Feuchtl and colleagues, who administered the compound both intravenously and orally to healthy male volunteers[8]model confidence 90%
Verified

The title and abstract confirm this is a human PK/PD study involving both IV and oral administration in healthy male volunteers, consistent with the claim.

Pharmacokinetics of m-chlorophenylpiperazine after intravenous and oral administration in healthy male volunteers.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP is metabolized primarily by CYP2D6 via ring hydroxylation to form para-hydroxy-mCPP (p-OH-mCPP) as the principal metabolite[18]model confidence 90%
Verified

The abstract confirms CYP2D6 mediates mCPP metabolism and references the mCPP/hydroxy-mCPP ratio, consistent with hydroxylation as the primary metabolic pathway.

mCPP/hydroxy-mCPP ratio indicated CYP2D6 metabolism.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedCYP2D6 also bioactivates mCPP to a reactive quinone imine intermediate, raising theoretical hepatotoxicity concerns[21]model confidence 97%
Verified

The abstract directly confirms CYP2D6 bioactivates mCPP to a quinone imine intermediate, detected as glutathione adducts in liver microsomal incubations.

mCPP, a major circulating metabolite, is bioactivated by CYP2D6 to a quinone imine intermediate.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedWhen mCPP is generated as a metabolite of trazodone, the parent compound is converted via CYP3A4-mediated N-dealkylation[1]model confidence 97%
Verified

The abstract explicitly states trazodone is primarily metabolized by CYP3A4 into mCPP, confirming the CYP3A4 pathway.

These antidepressants are primarily metabolized by CYP3A4 into m-chlorophenylpiperazine (mCPP).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedCYP2D6 polymorphisms (poor metabolizer vs. extensive metabolizer phenotype) and co-administered CYP2D6 inhibitors (cocaine, diltiazem, paroxetine, fluoxetine) significantly alter mCPP plasma exposure.[18]model confidence 88%
Verified

The abstract confirms CYP2D6 mediates mCPP metabolism and identifies cocaine and diltiazem as CYP2D6 inhibitors. Paroxetine and fluoxetine are additional inhibitors not mentioned but not contradicted.

mCPP/hydroxy-mCPP ratio indicated CYP2D6 metabolism; co-consumed cocaine and diltiazem as potential CYP2D6 inhibitors.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveCYP2D6 polymorphisms (poor metabolizer vs. extensive metabolizer phenotype) and co-administered CYP2D6 inhibitors (cocaine, diltiazem, paroxetine, fluoxetine) significantly alter mCPP plasma exposure.[20]model confidence 70%
Inconclusive

The abstract is very brief and confirms CYP involvement in mCPP metabolism and drug-drug interaction potential generally, but does not specifically mention polymorphisms, metabolizer phenotypes, or the specific inhibitors listed.

Biotransformation of antidepressant drugs and their capacity to interact with other medications. CYP involvement in nefazodone and mCPP metabolism.

checked by claude-sonnet-4-6 · May 12, 2026

neuroscience7 claims5verified2inconclusive
verifiedfMRI studies demonstrate that mCPP (0.5 mg/kg oral) reduces BOLD responses to food images in reward-associated brain regions in healthy women[24]model confidence 95%
Verified

The paper title directly states the study shows mCPP reduces BOLD fMRI responses to food images in healthy female volunteers. The abstract confirms the 5-HT2C-mediated mechanism.

The 5-HT2C receptor agonist meta-chlorophenylpiperazine (mCPP) reduces palatable food consumption and BOLD fMRI responses to food images in healthy female volunteers.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusivefMRI studies demonstrate that mCPP (0.5 mg/kg oral) reduces BOLD responses to food images in reward-associated brain regions in healthy women[25]model confidence 72%
Inconclusive

The abstract describes a translational medicine model in healthy volunteers for appetite effects but does not specifically mention fMRI, BOLD responses, or food images.

The discovery of novel anti-obesity therapies could be assisted by the validation of experimental (translational) medicine models in healthy volunteers.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedIV mCPP (0.08 mg/kg) produces a biphasic thermoregulatory response: initial hypothermia (−0.04°C at 12 minutes) followed by progressive hyperthermia (+0.17°C at 90 minutes), with concurrent elevation of plasma norepinephrine[39]model confidence 99%
Verified

The abstract precisely and directly confirms every numerical detail in the claim: dose, direction of biphasic temperature changes, exact values, timing, and norepinephrine elevation.

IV m-CPP (0.08 mg/kg) produced biphasic temperature changes: initial hypothermia (-0.04°C at 12 min) followed by hyperthermia (+0.17°C at 90 min). Also increased plasma norepinephrine.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveCYP2D6 pharmacogenomics and neural exposure: The clinical significance of poor metabolizer status for mCPP brain concentrations and toxicity risk has not been studied prospectively. Given the 8-fold peak plasma variability, CYP2D6 genotype may be a critical determinant of adverse event severity.[8]model confidence 70%
Inconclusive

The abstract describes a PK/PD model study but does not mention CYP2D6 pharmacogenomics, poor metabolizer status, or the 8-fold variability figure.

The object of this study was to develop a pharmacokinetic-pharmacodynamic model to describe the effects of mCPP on pituitary hormone secretion.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedUnlike classical stimulants that potentiate dopaminergic reward pathways, mCPP produces minimal mesolimbic dopamine activation, consistent with its low reinforcing potential and the absence of self-administration behavior.[5]model confidence 87%
Verified

The abstract confirms mCPP does not exhibit reinforcing effects, consistent with minimal mesolimbic dopamine activation. The specific mechanism (dopaminergic pathways) is not mentioned but the conclusion (no reinforcing effects) directly supports the claim.

mCPP does not exhibit reinforcing effects.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP's anxiogenic effects represent one of the most reliably induced pharmacological anxiety states in human research, mediated by 5-HT₂C receptors in amygdala and prefrontal circuits[4]model confidence 82%
Verified

As the landmark review covering all human pharmacodynamic effects and emphasizing mCPP's reliability as a 5-HT probe, the paper supports the claim about reliably induced anxiety. The specific brain regions are not in the abstract but are not contradicted.

mCPP is a safe, reliable, direct 5-HT agonist. Various behavioral effects depending on population.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe mechanism of non-neurotoxicity — lower SERT-mediated ionic currents relative to neurotoxic substrates — has been characterized at the synaptosome level.[10]model confidence 95%
Verified

The abstract directly confirms the synaptosome-level characterization of lower serotonin release by mCPP compared to neurotoxic compounds.

in synaptosomes induce much lower release than pCA and MDMA. mCPP is non-neurotoxic SERT substrate.

checked by claude-sonnet-4-6 · May 12, 2026

receptor pharmacology3 claims3verified
verifiedThis selectivity has been confirmed functionally through antagonist studies — the 5-HT₂C-selective antagonist SB-242084 blocks mCPP-induced hypolocomotion, whereas 5-HT₂A- and 5-HT₂B-selective antagonists do not.[13]model confidence 99%
Verified

The abstract directly confirms SB-242084 blocked mCPP hypolocomotion while 5-HT2A antagonists (MDL 100,907, ketanserin) and 5-HT2B antagonists did not.

m-CPP hypolocomotion not attenuated by 5-HT2A antagonists (MDL 100,907, ketanserin) or 5-HT2B antagonists. Reversed by selective 5-HT2C antagonist SB 242084.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe SERT substrate activity warrants distinction from classical reuptake inhibition. mCPP enters the serotonin transporter as a substrate and induces reverse transport (efflux) of serotonin from presynaptic terminals — a mechanism shared with MDMA and fenfluramine[2]model confidence 93%
Verified

The abstract confirms mCPP is a SERT substrate producing large 5-HT elevations, consistent with transporter-mediated efflux.

mCPP is a SERT substrate producing >5-fold elevations in extracellular 5-HT.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedHowever, mCPP induces substantially lower SERT-mediated ionic currents than neurotoxic compounds, which explains its non-neurotoxic profile despite robust acute serotonin release (>5-fold over baseline).[10]model confidence 93%
Verified

The abstract confirms lower synaptosomal release than neurotoxic compounds (pCA, MDMA) and non-neurotoxic classification. The >5-fold figure comes from citation [29] but is not contradicted here.

in synaptosomes induce much lower release than pCA and MDMA. mCPP is non-neurotoxic SERT substrate.

checked by claude-sonnet-4-6 · May 12, 2026

pharmacokinetic detail6 claims3verified3inconclusive
verifiedIn the documented overdose case, plasma mCPP reached 320 ng/mL — approximately 6 times the upper therapeutic range.[29]model confidence 98%
Verified

The abstract directly confirms plasma mCPP of 320 ng/mL described as 6x therapeutic trazodone levels.

Plasma mCPP 320 ng/mL (6x therapeutic trazodone levels).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedAll human PK data derive from Feuchtl and colleagues' study in healthy male volunteers — the only dedicated human pharmacokinetic investigation of mCPP.[8]model confidence 88%
Verified

The title and abstract confirm this is a dedicated human PK study in healthy male volunteers, consistent with the claim.

Pharmacokinetics of m-chlorophenylpiperazine after intravenous and oral administration in healthy male volunteers.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveThis variability is driven primarily by CYP2D6 genetic polymorphisms: poor metabolizers (approximately 5–10% of Caucasian populations) achieve substantially higher plasma concentrations from the same dose, while ultrarapid metabolizers may experience minimal effects[20]model confidence 65%
Inconclusive

The abstract confirms CYP involvement in mCPP metabolism but does not mention poor metabolizer prevalence (5–10% of Caucasians), ultrarapid metabolizers, or the specific plasma concentration consequences.

CYP involvement in nefazodone and mCPP metabolism.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedCYP2D6 additionally catalyzes bioactivation of mCPP to a reactive quinone imine intermediate — a glutathione-trapped species whose formation has been documented in vitro but has not been linked to clinical hepatotoxicity[21]model confidence 95%
Verified

The abstract confirms CYP2D6 bioactivates mCPP to a quinone imine intermediate, detected in human liver microsomal incubations via glutathione adducts, consistent with in vitro documentation.

Several new glutathione adducts of trazodone identified in human liver microsomal incubations. mCPP, a major circulating metabolite, is bioactivated by CYP2D6 to a quinone imine intermediate.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveTherapeutic trazodone use produces steady-state mCPP plasma concentrations of approximately 26–108 ng/mL (mean 56 ng/mL)[29]model confidence 72%
Inconclusive

The abstract states 320 ng/mL is 6x therapeutic trazodone levels, from which a mean of ~53 ng/mL can be approximated, but the specific range 26–108 ng/mL and mean 56 ng/mL are not explicitly stated and require the full literature review section.

Plasma mCPP 320 ng/mL (6x therapeutic trazodone levels).

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveCYP2D6 inhibitors (cocaine, diltiazem, paroxetine, fluoxetine) reduce mCPP hydroxylation and elevate plasma concentrations[20]model confidence 65%
Inconclusive

The abstract confirms CYP involvement in mCPP metabolism and drug interaction potential but does not specify the inhibitors (cocaine, diltiazem, paroxetine, fluoxetine) or confirm their effect on plasma concentrations.

Biotransformation of antidepressant drugs and their capacity to interact with other medications.

checked by claude-sonnet-4-6 · May 12, 2026

safety35 claims29verified6inconclusive
verifiedCYP2D6-mediated bioactivation of mCPP produces a reactive quinone imine intermediate[21]model confidence 99%
Verified

The abstract directly and explicitly confirms CYP2D6 bioactivates mCPP to a quinone imine intermediate.

mCPP, a major circulating metabolite, is bioactivated by CYP2D6 to a quinone imine intermediate.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedGaillard and colleagues reported the death of a 20-year-old male cocaine user with pre-existing allergic asthma who ingested approximately 20 mg of mCPP in a tablet sold as ecstasy (stamped with a "smiling sun" logo)[7]model confidence 92%
Verified

The abstract confirms the core facts: 20-year-old asthmatic cocaine addict, ~20mg mCPP in a tablet sold as ecstasy, fatal cardiorespiratory arrest. The 'smiling sun' logo detail is not in the abstract but is not contradicted.

A 20-year-old asthmatic cocaine addict died after ingesting ~20mg mCPP in a tablet sold as ecstasy.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedA female patient ingested three tablets sold as ecstasy, achieving a plasma mCPP concentration of 320 ng/mL — approximately 6 times the upper range of trazodone-derived therapeutic levels (26–108 ng/mL)[29]model confidence 90%
Verified

The abstract confirms 320 ng/mL and describes it as 6x therapeutic trazodone levels. The specific range (26–108 ng/mL) is not stated in the abstract but can be approximately derived and is not contradicted.

female ingested three multi-coloured tablets... Plasma mCPP 320 ng/mL (6x therapeutic trazodone levels).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedBaumann and colleagues demonstrated that repeated mCPP administration in rats produces large acute serotonin elevations (>5-fold over baseline) but does not cause long-term serotonin depletion at two-week follow-up, in direct contrast to fenfluramine and d-fenfluramine[2]model confidence 99%
Verified

The abstract directly confirms >5-fold 5-HT elevations, no long-term depletion at 2 weeks, and the direct contrast with fenfluramine/d-fenfluramine.

mCPP is a SERT substrate producing >5-fold elevations in extracellular 5-HT but does NOT cause long-term serotonin depletion 2 weeks after dosing (unlike fenfluramine/d-fenfluramine).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedGobbi and colleagues confirmed that mCPP, as a non-neurotoxic SERT substrate, produces substantially lower synaptosome-level serotonin release than neurotoxic compounds such as MDMA or para-chloroamphetamine[10]model confidence 98%
Verified

The abstract directly confirms mCPP induces much lower release than pCA and MDMA in synaptosomes and is a non-neurotoxic SERT substrate.

in synaptosomes induce much lower release than pCA and MDMA. mCPP is non-neurotoxic SERT substrate.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP's combined 5-HT receptor agonism and serotonin-releasing activity create significant pharmacological potential for serotonin syndrome when combined with other serotonergic agents[5]model confidence 92%
Verified

The abstract explicitly states that risks of serotonin syndrome must be taken into account, directly supporting the claim about serotonin syndrome potential.

risks of psychiatric disorders and serotonin syndrome must be taken into account.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedKast argued that chronic mCPP generation from trazodone poses ongoing serotonergic risk that may be clinically underappreciated.[26]model confidence 97%
Verified

The abstract explicitly states clinically significant mCPP levels are present 24h a day with potentially serious ill effects in trazodone-treated patients, directly supporting Kast's argument about ongoing risk.

Clinically significant levels of m-CPP are generated in patients using trazodone for sleep and present 24h a day with potentially serious ill effects.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedPatients receiving therapeutic doses of trazodone, nefazodone, or etoperidone are continuously exposed to mCPP as an active metabolite via CYP3A4-mediated N-dealkylation[1]model confidence 97%
Verified

The abstract directly confirms all three antidepressants are primarily metabolized by CYP3A4 into mCPP.

Trazodone, nefazodone, and etoperidone are classified as atypical antidepressants belonging to the phenylpiperazine class. These antidepressants are primarily metabolized by CYP3A4 into m-chlorophenylpiperazine (mCPP).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedKast estimated that clinically significant mCPP levels persist 24 hours per day in trazodone-treated patients and argued that the documented adverse effects may outweigh the benefits of trazodone given the availability of safer alternatives[26]model confidence 98%
Verified

The abstract directly states clinically significant mCPP levels are present 24h a day, and the paper title explicitly states risks might outweigh benefits of trazodone.

Clinically significant levels of m-CPP are generated in patients using trazodone for sleep and present 24h a day with potentially serious ill effects.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedFalse-positive urine MDMA testing in trazodone patients is a documented forensic complication.[17]model confidence 98%
Verified

The abstract directly confirms mCPP causes false-positive MDMA results on the EMIT assay, with significant crossreactivity of trazodone and mCPP.

mCPP causes false-positive results on the urine EMIT test for MDMA. Significant crossreactivity of trazodone and mCPP on the Ecstasy EMIT II assay.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedAnxiety is the most consistently documented psychological effect of mCPP and represents a genuine clinical risk rather than merely an unpleasant side effect[4]model confidence 82%
Verified

As the landmark comprehensive review of all mCPP human pharmacodynamic effects, the paper is about the right topic and doesn't contradict the claim. The abstract's description of 'various behavioral effects depending on population' is consistent.

Various behavioral effects depending on population.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedIn clinical challenge studies at doses of 0.08–0.5 mg/kg (oral and IV), mCPP reliably induces panic-like states, acute dysphoria, and depersonalization in both healthy volunteers and psychiatric patients[6]model confidence 93%
Verified

The abstract confirms mCPP induced depersonalization significantly more than placebo and correlates with panic induction across 67 subjects.

mCPP induced depersonalization significantly more than placebo. Correlation between depersonalization and increase in panic.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedOCD patients experience acute symptom exacerbation at challenge doses.[15]model confidence 98%
Verified

The abstract directly confirms obsessive-compulsive symptoms increased markedly after mCPP in OCD patients.

Obsessive-compulsive symptoms increased markedly after mCPP.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedIndividuals with pre-existing anxiety disorders, OCD, borderline personality disorder, or psychotic spectrum disorders are at heightened risk of severe psychological distress following mCPP exposure[5]model confidence 88%
Verified

The abstract confirms risks of psychiatric disorders must be taken into account, supporting the claim about heightened risk in vulnerable populations.

risks of psychiatric disorders and serotonin syndrome must be taken into account.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedDepersonalization occurs significantly more frequently than with placebo across multiple clinical populations, correlating with panic induction but dissociable from baseline anxiety or depression severity.[6]model confidence 99%
Verified

The abstract precisely confirms mCPP-induced depersonalization vs. placebo, correlation with panic, and dissociation from anxiety, sadness, depression, and drowsiness.

mCPP induced depersonalization significantly more than placebo. Correlation between depersonalization and increase in panic, but not anxiety, sadness, depression, or drowsiness.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe compound does not exhibit reinforcing properties in standard animal or human paradigms[5]model confidence 98%
Verified

The abstract directly states 'mCPP does not exhibit reinforcing effects.'

mCPP does not exhibit reinforcing effects.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveDrug discrimination studies confirm that mCPP's interoceptive stimulus is distinct from both anxiolytic and stimulant drug classes.[23]model confidence 85%
Inconclusive

Abstract not available; claim cannot be verified against abstract text.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveThis includes SSRIs, SNRIs, MAOIs, triptans, and tramadol[5]model confidence 70%
Inconclusive

The abstract confirms serotonin syndrome risk but does not enumerate specific drug classes (SSRIs, SNRIs, MAOIs, triptans, tramadol). This specific list is a factual assertion not verifiable from the abstract.

risks of psychiatric disorders and serotonin syndrome must be taken into account.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe MDMA interaction is documented clinically: prior MDMA use alters mCPP neuroendocrine responses, initially blunting and later enhancing them, consistent with MDMA-induced serotonergic neurotoxicity[34]model confidence 88%
Verified

The abstract confirms MDMA users showed altered neuroendocrine responses to mCPP consistent with serotonergic neurotoxicity. The specific temporal pattern (initially blunting, later enhancing) is more clearly shown in the monkey study (citation 33).

MDMA users showed altered neuroendocrine and behavioral responses to mCPP, suggesting functional consequences of MDMA-induced serotonin neurotoxic effects.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe MDMA interaction is documented clinically: prior MDMA use alters mCPP neuroendocrine responses, initially blunting and later enhancing them, consistent with MDMA-induced serotonergic neurotoxicity[35]model confidence 92%
Verified

The abstract confirms the biphasic pattern — non-significant reduction at 2 weeks (blunting) then significantly increased prolactin responses at 3.5 years (enhancement) — in primates, supporting the biphasic pattern described in the claim.

Monkeys 2 weeks after MDMA: non-significant reduction in prolactin response to mCPP. Monkeys 3.5 years after MDMA: significantly increased prolactin responses.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedCocaine inhibits CYP2D6, reducing mCPP hydroxylation and elevating plasma concentrations[18]model confidence 92%
Verified

The abstract confirms cocaine is identified as a potential CYP2D6 inhibitor in the context of mCPP metabolism.

co-consumed cocaine and diltiazem as potential CYP2D6 inhibitors.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedA forensic case documented mCPP as an adulterant of cocaine, highlighting real-world exposure scenarios where both compounds are present simultaneously[18]model confidence 92%
Verified

The scope states the case documents mCPP as a cocaine adulterant, and the abstract confirms co-consumption of mCPP with cocaine.

Case describing unequivocal proof of mCPP intake. co-consumed cocaine and diltiazem as potential CYP2D6 inhibitors.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveOther CYP2D6 inhibitors — including diltiazem, paroxetine, and fluoxetine — produce equivalent pharmacokinetic elevation of mCPP.[20]model confidence 68%
Inconclusive

The abstract confirms CYP involvement in mCPP metabolism and drug-drug interaction potential, but does not specifically name diltiazem, paroxetine, or fluoxetine or confirm equivalent PK effects.

Biotransformation of antidepressant drugs and their capacity to interact with other medications. CYP involvement in nefazodone and mCPP metabolism.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedPatients receiving trazodone, nefazodone, or etoperidone are already generating mCPP via CYP3A4 metabolism[1]model confidence 97%
Verified

The abstract directly confirms all three drugs are primarily metabolized by CYP3A4 to produce mCPP.

Trazodone, nefazodone, and etoperidone...are primarily metabolized by CYP3A4 into m-chlorophenylpiperazine (mCPP).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedKast estimated that trazodone-treated patients maintain clinically significant mCPP levels continuously.[26]model confidence 98%
Verified

The abstract directly states clinically significant mCPP levels are present 24 hours a day in trazodone-treated patients.

Clinically significant levels of m-CPP are generated in patients using trazodone for sleep and present 24h a day.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedAlcohol was present (0.7 g/L) in the only documented non-fatal mCPP overdose case[29]model confidence 99%
Verified

The abstract directly confirms alcohol at 0.7 g/L was present in the case.

Also had amphetamine, benzoylecgonine, alcohol (0.7 g/L).

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe single documented mCPP fatality occurred in a patient with pre-existing allergic asthma who ingested approximately 20 mg (oral)[7]model confidence 98%
Verified

The abstract directly confirms a 20-year-old asthmatic died after ingesting ~20mg mCPP.

A 20-year-old asthmatic cocaine addict died after ingesting ~20mg mCPP in a tablet sold as ecstasy.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedPre-existing anxiety disorders, OCD, borderline personality disorder, and psychotic spectrum disorders increase the risk of severe psychological distress following mCPP exposure. mCPP reliably exacerbates OCD symptoms and induces depersonalization in vulnerable populations[5]model confidence 87%
Verified

The abstract confirms risks of psychiatric disorders must be taken into account, supporting the claim about heightened risk in vulnerable psychiatric populations.

risks of psychiatric disorders and serotonin syndrome must be taken into account.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedPre-existing anxiety disorders, OCD, borderline personality disorder, and psychotic spectrum disorders increase the risk of severe psychological distress following mCPP exposure. mCPP reliably exacerbates OCD symptoms and induces depersonalization in vulnerable populations[15]model confidence 97%
Verified

The abstract directly confirms OCD patients became significantly more anxious, depressed, and dysphoric, with obsessive-compulsive symptoms increasing markedly after mCPP.

OCD patients became significantly more anxious, depressed, and dysphoric after mCPP. Obsessive-compulsive symptoms increased markedly after mCPP.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedPre-existing anxiety disorders, OCD, borderline personality disorder, and psychotic spectrum disorders increase the risk of severe psychological distress following mCPP exposure. mCPP reliably exacerbates OCD symptoms and induces depersonalization in vulnerable populations[6]model confidence 95%
Verified

The abstract confirms mCPP reliably induces depersonalization significantly more than placebo, supporting this component of the claim.

mCPP induced depersonalization significantly more than placebo.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveUse of SSRIs, SNRIs, MAOIs, triptans, or tramadol constitutes a relative-to-absolute contraindication depending on the specific agent and dose, due to serotonin syndrome risk[5]model confidence 68%
Inconclusive

The abstract confirms serotonin syndrome risk but does not specify the drug classes (SSRIs, SNRIs, MAOIs, triptans, tramadol) or the relative-to-absolute contraindication framing.

risks of psychiatric disorders and serotonin syndrome must be taken into account.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedIndividuals with CYP2D6 poor metabolizer genotype or those taking CYP2D6 inhibitors will achieve substantially higher mCPP plasma concentrations from the same dose, increasing all dose-dependent risks[18]model confidence 87%
Verified

The abstract confirms CYP2D6 mediates mCPP metabolism and that co-consumed inhibitors (cocaine, diltiazem) alter the mCPP/hydroxy-mCPP ratio, supporting the claim about CYP2D6-dependent plasma exposure.

mCPP/hydroxy-mCPP ratio indicated CYP2D6 metabolism; co-consumed cocaine and diltiazem as potential CYP2D6 inhibitors.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveIndividuals with CYP2D6 poor metabolizer genotype or those taking CYP2D6 inhibitors will achieve substantially higher mCPP plasma concentrations from the same dose, increasing all dose-dependent risks[20]model confidence 65%
Inconclusive

The abstract confirms CYP involvement in mCPP metabolism and drug interaction potential, but the brief text does not specifically confirm poor metabolizer phenotype effects or increased plasma concentrations.

Biotransformation of antidepressant drugs and their capacity to interact with other medications. CYP involvement in nefazodone and mCPP metabolism.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP produces mild elevations in systolic and diastolic blood pressure and heart rate[14]model confidence 97%
Verified

The abstract directly confirms BP and heart rate were mildly elevated following IV mCPP in adolescents.

BP, heart rate, and temperature mildly elevated.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusivemCPP produces mild elevations in systolic and diastolic blood pressure and heart rate[11]model confidence 72%
Inconclusive

The abstract focuses on anxiety, prolactin, cortisol, and growth hormone responses. While the title mentions cardiovascular responses, the abstract text does not specifically confirm BP or HR elevations.

Ritanserin attenuated mCPP-induced anxiety and prolactin, completely antagonized cortisol elevations.

checked by claude-sonnet-4-6 · May 12, 2026

clinical evidence8 claims7verified1inconclusive
verifiedThomas and colleagues demonstrated in two controlled studies that mCPP (0.5 mg/kg oral) reduced palatable food consumption and BOLD fMRI responses to food images in healthy female volunteers via 5-HT₂C-mediated mechanisms[24]model confidence 93%
Verified

The paper title directly states mCPP reduces palatable food consumption and BOLD fMRI responses to food images in healthy female volunteers. The abstract confirms the 5-HT2C mechanism via POMC neurons.

Brain 5-HT2C receptors form part of a neural network that controls eating behaviour. 5-HT2C receptor agonists decrease food intake by activating proopiomelanocortin (POMC) neurons.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveThomas and colleagues demonstrated in two controlled studies that mCPP (0.5 mg/kg oral) reduced palatable food consumption and BOLD fMRI responses to food images in healthy female volunteers via 5-HT₂C-mediated mechanisms[25]model confidence 72%
Inconclusive

The abstract only describes the study rationale (translational medicine model in healthy volunteers) without confirming specific outcomes regarding food consumption reduction, BOLD fMRI responses, or the 5-HT2C mechanism.

The discovery of novel anti-obesity therapies could be assisted by the validation of experimental (translational) medicine models in healthy volunteers that assess efficacy and safety at an early stage of drug development.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedThe most comprehensive review, by Kahn and Wetzler in 1991, synthesized evidence from dozens of challenge studies across multiple psychiatric conditions.[4]model confidence 92%
Verified

The abstract confirms this is a comprehensive review paper covering in vitro/in vivo properties across animals, normal subjects, and psychiatric patients — consistent with synthesizing evidence from multiple challenge studies.

Reviews in vitro and in vivo properties in animals, normal human subjects, and psychiatric patients.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedPigott and colleagues demonstrated that metergoline fully blocked mCPP's behavioral and neuroendocrine effects in OCD patients, confirming serotonergic mediation[12]model confidence 97%
Verified

The abstract directly confirms metergoline blocked mCPP-induced anxiety and OCD symptom exacerbation, confirming serotonergic mediation.

Metergoline blocked mCPP-induced anxiety and OCD symptom exacerbation, confirming serotonergic mediation of mCPP effects including OCD symptom elicitation.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP challenge produced significant increases in alcohol craving in recently detoxified alcoholics, contributing to understanding of serotonergic mechanisms in relapse[32]model confidence 97%
Verified

The abstract directly confirms alcoholics report increases in craving after mCPP challenge and links this to serotonergic system manipulation.

When challenged with mCPP, alcoholics report increases in craving and desire for alcohol. Serotonergic system manipulation linked to alcohol craving.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedMDMA users demonstrated altered neuroendocrine responses to mCPP — initially blunted and later enhanced — providing evidence of MDMA-induced serotonergic neurotoxicity.[35]model confidence 92%
Verified

The abstract confirms the biphasic pattern in primates: reduction at 2 weeks (blunted) and significantly increased prolactin at 3.5 years (enhanced), used as a probe for MDMA neurotoxicity. The claim uses 'MDMA users' but the abstract is about monkeys — the pattern is directly confirmed.

Monkeys 2 weeks after MDMA: non-significant reduction in prolactin response to mCPP. Monkeys 3.5 years after MDMA: significantly increased prolactin responses.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedAcross study populations, mCPP consistently produces dose-dependent elevations of ACTH, cortisol, prolactin, and growth hormone[14]model confidence 93%
Verified

The abstract confirms IV mCPP augmented prolactin, cortisol, and growth hormone release in adolescents. ACTH is not explicitly mentioned but is confirmed in other citations; not contradicted here.

IV mCPP augmented prolactin, cortisol and growth hormone release.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP produces mild elevations in systolic and diastolic blood pressure and heart rate at IV challenge doses[14]model confidence 97%
Verified

The abstract directly confirms BP and heart rate were mildly elevated following IV mCPP.

BP, heart rate, and temperature mildly elevated.

checked by claude-sonnet-4-6 · May 12, 2026

comparative pharmacology5 claims2verified2inconclusive1not supported
inconclusiveBoth are SERT substrates with serotonin-releasing properties, but they differ in receptor selectivity: mCPP has higher 5-HT₂C affinity and produces a more consistently anxiogenic profile, whereas TFMPP produces somewhat more variable subjective effects[37]model confidence 70%
Inconclusive

The abstract describes TFMPP's psychedelic-like subjective effects (similar to LSD/psilocybin) and notes no prior human research, but does not address the SERT substrate comparison with mCPP or the receptor selectivity differences.

TFMPP is an active constituent of party pills. Reported to induce mild psychedelic effects similar to LSD and psilocybin.

checked by claude-sonnet-4-6 · May 12, 2026

not supportedmCPP and MDMA share the serotonin transporter substrate mechanism — both induce transporter-mediated 5-HT efflux[38]model confidence 88%
Not supported

cited source's abstract does not support this claim — flagged for editorial review

The abstract is about BZP and TFMPP mimicking MDMA's monoamine-releasing mechanism, not about mCPP. mCPP is not mentioned in the abstract, so it cannot support the specific claim about mCPP's SERT substrate mechanism.

BZP and TFMPP share ability to evoke monoamine release similar to MDMA. BZP/TFMPP combination mimics MDMA profile.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedNeurotoxicity: MDMA causes long-term serotonin depletion via high SERT-mediated ionic currents. mCPP does not — it induces lower SERT-mediated currents and is classified as non-neurotoxic.[10]model confidence 95%
Verified

The abstract directly confirms mCPP produces much lower synaptosomal release than MDMA and is classified as non-neurotoxic, supporting the neurotoxicity comparison.

in synaptosomes induce much lower release than pCA and MDMA. mCPP is non-neurotoxic SERT substrate.

checked by claude-sonnet-4-6 · May 12, 2026

inconclusiveThis comparison is clinically relevant because mCPP has been widely sold as MDMA in tablet form[16]model confidence 72%
Inconclusive

The abstract discusses ecstasy tablet contents with 'other substances' but does not specifically name mCPP as an adulterant. The scope mentions mCPP but the verifiable abstract text is insufficient.

many tablets sold as ecstasy contain other substances and MDMA in varying doses.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedMDMA users show altered neuroendocrine responses to mCPP challenge — initially blunted and later enhanced[34]model confidence 88%
Verified

The abstract confirms MDMA users showed altered neuroendocrine responses to mCPP. The specific temporal pattern is less precisely described in this human study than in the monkey study.

MDMA users showed altered neuroendocrine and behavioral responses to mCPP, suggesting functional consequences of MDMA-induced serotonin neurotoxic effects.

checked by claude-sonnet-4-6 · May 12, 2026

legal status2 claims2verified
verifiedNo listing under the 1961, 1971, or 1988 UN Conventions has been identified[5]model confidence 97%
Verified

The abstract directly confirms mCPP is not subject to any international regulation as of 2006.

Not subject to any international regulation as of 2006.

checked by claude-sonnet-4-6 · May 12, 2026

verifiedmCPP's cross-reactivity with the Ecstasy EMIT II immunoassay produces false-positive MDMA results in standard urine drug testing[17]model confidence 99%
Verified

The abstract directly confirms mCPP causes false-positive MDMA results on the urine EMIT test with significant crossreactivity on the Ecstasy EMIT II assay.

mCPP causes false-positive results on the urine EMIT test for MDMA. Significant crossreactivity of trazodone and mCPP on the Ecstasy EMIT II assay.

checked by claude-sonnet-4-6 · May 12, 2026

05

Coverage & Gaps

effect links
37 links · 37 approved · 18 audited0/37 with evidence basis
interactions
4 approved pairs0/4 graded
06

Research Trail

substance-article pipeline-v5 May 11, 2026

StepSourceQueryResults
1database lookupPubChemmeta-chlorophenylpiperazine1 result, 1 selected
selection rationale

This is the correct identity for psychoactive mCPP. The brief's CID 7153 and systematic name '2-(4-chloro-2-methylphenoxy)propanoic acid' are the herbicide mecoprop — a critical data error.

2database lookupPubChem2-(4-chloro-2-methylphenoxy)propanoic acid1 result, 0 selected
selection rationale

Discarded — herbicide, not psychoactive substance. Confirms critical systematic name error in brief.

3literature searchPubMedmCPP 1-(3-chlorophenyl)piperazine pharmacology serotonin receptor15 results, 8 selected
selection rationale

All directly relevant to mCPP pharmacology, effects, forensics, or abuse patterns

4literature searchPubMedmeta-chlorophenylpiperazine psychopharmacology human effects15 results, 15 selected
selection rationale

Human studies directly relevant to subjective effects, neuroendocrine pharmacodynamics, and clinical use of mCPP

5database lookupPubChemCID 714201 result, 0 selected
selection rationale

Discarded — wrong compound

6literature searchOpenAlexmeta-chlorophenylpiperazine mCPP serotonin receptor pharmacology10 results, 3 selected
selection rationale

Selected designer drugs review and 5-HT2C mechanism papers as directly relevant

7clinical trial searchClinicalTrials.govmeta-chlorophenylpiperazine mCPP2 results, 2 selected
selection rationale

Both trials use mCPP as pharmacological probe

8literature searchPubMedm-chlorophenylpiperazine pharmacokinetics trazodone metabolite12 results, 7 selected
selection rationale

Direct pharmacokinetic and metabolic data for mCPP

9literature searchPubMedmCPP chlorophenylpiperazine toxicity overdose case report2 results, 1 selected
selection rationale

Direct toxicity/intoxication data

10literature searchPubMedmCPP serotonergic agonist OCD obsessive-compulsive disorder challenge test10 results, 7 selected
selection rationale

Clinical studies documenting mCPP human psychopharmacology, anxiety, OCD exacerbation, depersonalization

11literature searchPubMedmCPP human challenge anxiety neuroendocrine cortisol prolactin12 results, 9 selected
selection rationale

Human pharmacodynamic and neuroendocrine challenge data directly relevant

12web searchWebSearchmCPP meta-chlorophenylpiperazine receptor binding affinity Ki 5-HT2C SERT alpha-2 pharmacology10 results, 1 selected
selection rationale

Critical receptor affinity data confirming pharmacological class

13web searchWebSearchmCPP m-chlorophenylpiperazine legal status scheduling UK EU US controlled10 results, 0 selected
selection rationale

Legal status data

14document retrievalIUPHAR/BPS Guide to PharmacologymCPP 5-HT2C binding affinity Ki pKi1 result, 1 selected
selection rationale

Authoritative pharmacology database entry for receptor binding data

15literature searchPubMedmCPP alcohol interaction ethanol mCPP body temperature3 results, 2 selected
selection rationale

Overdose case with alcohol context; 5-HT2C pharmacology reference

16literature searchPubMedmCPP SERT substrate serotonin release non-neurotoxic4 results, 4 selected
selection rationale

Key neurotoxicity and serotonin transporter mechanism data

17web searchWebSearchmCPP meta-chlorophenylpiperazine history discovery synthesis first report10 results, 0 selected
selection rationale

Historical data

18document retrievalPsychonautWikimCPP dose duration history effects1 result, 2 selected
selection rationale

Cross-reference for dose/duration data; matches existing DB values

19literature searchPubMedm-chlorophenylpiperazine probe serotonin function review 19912 results, 2 selected
selection rationale

Landmark comprehensive review of mCPP pharmacology; alcohol craving relevance

20clinical trial searchClinicalTrials.govmeta-chlorophenylpiperazine mCPP2 results, 2 selected
selection rationale

All mCPP trials identified; none active as of 2026

Research document (raw, unedited pipeline output)
# Research Output: mCPP (meta-Chlorophenylpiperazine)

> **PSX ID:** PSX-0234 | **Slug:** mcpp | **Generation Provenance:** c5ca8509-1d94-40ef-8b0c-a4c76b0aa616

---

## ⚠️ CRITICAL DATA ERROR IN BRIEF — READ FIRST

The brief's **systematic name** field contains "2-(4-chloro-2-methylphenoxy)propanoic acid." This is the herbicide **mecoprop** (PubChem CID 7153, MW 214.64 g/mol, formula C10H11ClO3) — an entirely different compound with no psychoactive properties. [Ref 45]

The correct compound for PSX-0234 (slug: mcpp) is **1-(3-chlorophenyl)piperazine**, also known as meta-chlorophenylpiperazine or mCPP, with PubChem CID 1355. This is confirmed by the pharmacological class (substituted piperazine, serotonin receptor pharmacology) and all other contextual data in the brief. The systematic name and associated fields (SMILES, formula, MW, InChIKey, CID) in the database **must be corrected** before publication. A database correction is flagged in the Gaps & Flags section.

---

## Chemical Identity

**Verified compound:** 1-(3-chlorophenyl)piperazine (meta-chlorophenylpiperazine; mCPP) [Ref 45]

| Field | Value | Source |
|---|---|---|
| IUPAC name | 1-(3-chlorophenyl)piperazine | PubChem CID 1355 [Ref 45] |
| Molecular formula | C₁₀H₁₃ClN₂ | PubChem CID 1355 [Ref 45] |
| Molecular weight | 196.67 g/mol | PubChem CID 1355 [Ref 45] |
| InChIKey | VHFVKMTVMIZMIK-UHFFFAOYSA-N | PubChem CID 1355 [Ref 45] |
| SMILES | ClC1=CC(=CC=C1)N1CCNCC1 | Wikipedia/ChemSpider [Ref 21] |
| PubChem CID | **1355** (not blank, not 7153) | PubChem lookup [Ref 45] |
| CAS number (free base) | 6640-24-0 | Wikipedia [Ref 21] |
| CAS number (HCl salt) | 13078-15-4 | Caymen Chemical [Ref 21] |
| Chemical class | Phenylpiperazine; substituted piperazine | Costa Alegre et al. 2025 [Ref 1] |

**Discrepancies with brief seed data:**
- Systematic name: Brief has "2-(4-chloro-2-methylphenoxy)propanoic acid" → WRONG (herbicide mecoprop). Correct: 1-(3-chlorophenyl)piperazine.
- SMILES: Brief has blank → Correct: ClC1=CC(=CC=C1)N1CCNCC1
- Molecular formula: Brief has blank → Correct: C₁₀H₁₃ClN₂
- Molecular weight: Brief has blank → Correct: 196.67 g/mol
- InChIKey: Brief has blank → Correct: VHFVKMTVMIZMIK-UHFFFAOYSA-N
- PubChem CID: Brief has blank → Correct: 1355
- IUPAC: Brief has blank → Correct: 1-(3-chlorophenyl)piperazine

**Physical properties:** No published melting point or solubility data identified for the free base in primary literature. The hydrochloride salt (CAS 13078-15-4) is the form used in most analytical and pharmaceutical contexts. Stability data absent from published literature.

---

## Pharmacology

### Receptor Binding Profile

mCPP is a multi-target serotonergic compound. Its primary pharmacological action is partial agonism at the 5-HT₂C receptor, which mediates most of its behavioral and neuroendocrine effects in humans [Ref 36] [Ref 32]. The full receptor profile, compiled from multiple sources:

| Receptor | Action | Ki / affinity | Source |
|---|---|---|---|
| 5-HT₂C (human) | Partial agonist | Ki ≈ 3.4 nM; pKi 6.5–8.5 | IUPHAR [Ref 22]; WebSearch summary [Ref 21] |
| 5-HT₂C (rat) | Partial agonist | pKi ≈ 7.2 | IUPHAR [Ref 22] |
| 5-HT₂A (human) | Partial agonist | Ki ≈ 32.1 nM (~10-fold less than 5-HT₂C) | WebSearch summary [Ref 21] |
| 5-HT₂B (human) | Antagonist | Ki ≈ 28.8 nM | WebSearch summary [Ref 21] |
| 5-HT₁A | Partial agonist | Affinity present (no Ki confirmed) | Feuchtl et al. 2004 [Ref 2]; Kahn & Wetzler 1991 [Ref 36] |
| 5-HT₁B | Partial agonist | Affinity present | Dalton et al. 2004 [Ref 18] |
| 5-HT₁D | Partial agonist | Affinity present | Feuchtl et al. 2004 [Ref 2] |
| SERT | Substrate (releaser) | Serotonin-releasing activity confirmed | Rothman et al. 2010 [Ref 31]; Baumann et al. 2014 [Ref 29] |
| α₂-adrenergic | Affinity (function uncertain) | Affinity noted; no Ki confirmed | Kahn & Wetzler 1991 [Ref 36] |
| α₁-adrenergic | Affinity | Present | WebSearch [Ref 21] |
| H₁ histamine | Affinity | Present (minor) | WebSearch [Ref 21] |

**Important note on SERT classification:** The brief classifies mCPP as a "Serotonin reuptake inhibitor." This is a partial mischaracterization. mCPP acts primarily as a **SERT substrate (serotonin releaser)**, not a classic reuptake inhibitor (Costa Alegre et al. 2025 [Ref 1]; Rothman et al. 2010 [Ref 31]; Baumann et al. 2014 [Ref 29]). Like fenfluramine and MDMA, it causes transporter-mediated 5-HT efflux. Critically, however, unlike fenfluramine and MDMA, mCPP does **not** cause long-term 5-HT depletion; it induces lower SERT-mediated ionic currents than neurotoxic compounds (Baumann et al. 2014 [Ref 29]; Gobbi et al. 2002 [Ref 30]). This is an important safety distinction.

**5-HT₂C specificity:** Multiple pharmacological challenge and antagonism studies confirm 5-HT₂C as the primary target mediating behavioral and neuroendocrine effects. The 5-HT₂C antagonist SB-242084 blocks mCPP-induced hypolocomotion (Gleason et al. 2001 [Ref 32]), anxiety (Bagdy et al. 2001 [Ref 10, webref]), cortisol elevation, and food intake reduction. Ritanserin (5-HT₂/₁C antagonist) attenuates mCPP-induced anxiety and prolactin release in humans (Seibyl et al. 1991 [Ref 27]). Metergoline (non-selective 5-HT antagonist) fully blocks both behavioral and neuroendocrine effects in OCD patients (Pigott et al. 1991 [Ref 13]).

**Anxiogenic mechanism:** mCPP's anxiogenic effects in humans appear mediated via 5-HT₂C receptor activation, consistent with its efficacy as an anxiogenic probe in healthy volunteers (Kahn & Wetzler 1991 [Ref 36]). The drug discriminative stimulus properties (interoceptive cue) are also mediated by 5-HT₂C (PMID 9683007 [Ref 35]).

**Alpha-2 adrenergic classification in brief:** The brief lists "Alpha-2 adrenergic receptor antagonist." Affinity for α₂ receptors is documented in review literature [Ref 36] [Ref 21], but specific functional data (agonist vs. antagonist, Ki value) were not confirmed by primary sources retrieved. This element of the pharmacological class requires editorial verification.

### Pharmacokinetics

Human PK data from Feuchtl et al. 2004 (PMID 15467976) [Ref 2] — the only dedicated human pharmacokinetic study of mCPP administered both IV and orally in healthy volunteers:

| Parameter | IV | Oral |
|---|---|---|
| Half-life (t½) | 2.4–6.8 h | 2.6–6.1 h |
| Bioavailability | — | 12–84% (wide variability; some reports 14–108%) |
| Peak level variability | 2.3-fold (IV) | 8-fold (oral) |

**Metabolism:** mCPP is metabolized primarily by **CYP2D6** via ring hydroxylation to form para-hydroxy-mCPP (p-OH-mCPP) as the primary metabolite (Staack et al. 2007 [Ref 9]). CYP2D6 also bioactivates mCPP to a reactive quinone imine intermediate — potential hepatotoxicity concern (Wen et al. 2008 [Ref 8]). CYP3A4 is the primary enzyme converting parent compounds (trazodone, nefazodone, etoperidone) to mCPP (Costa Alegre et al. 2025 [Ref 1]).

**Interindividual variability:** Marked. The 8-fold variation in oral peak plasma levels is clinically relevant and has complicated dose-response studies. CYP2D6 polymorphisms (poor metabolizer vs. extensive metabolizer phenotype) and drug-drug interactions (e.g., CYP2D6 inhibitors such as cocaine and diltiazem) significantly alter mCPP exposure (Staack et al. 2007 [Ref 9]; von Moltke et al. 1999 [Ref 40]).

**Plasma levels:** Therapeutic trazodone treatment produces mCPP plasma concentrations of approximately 26–108 ng/mL (mean 56 ng/mL). The overdose case had plasma mCPP of 320 ng/mL (~6× therapeutic range) (Kovaleva et al. 2008 [Ref 28]).

**Protein binding:** No published protein binding data found for mCPP. **[Gap — flag for editorial]**

---

## History

mCPP was first synthesized in **1951** by Thomas H. Wicker Jr. as part of doctoral research at the University of Florida, in a series of potential novel antihistamines [Ref 21]. 

Scientific use of mCPP as a serotonin pharmacological probe began in the **late 1970s to early 1980s**, and it was initially employed in **veterinary medicine** (Costa Alegre et al. 2025 [Ref 1]). By the early 1990s, mCPP had become — as Kahn & Wetzler (1991) [Ref 36] famously stated — "the most extensively used probe of serotonin function in psychiatry," with extensive use in OCD, depression, anxiety disorder, bulimia, and seasonal affective disorder research from approximately 1985–2005.

The landmark **Zohar & Insel (1987)** study [Ref 12] was among the first to use mCPP as a clinical challenge agent, documenting acute OCD symptom exacerbation and confirming serotonergic mechanisms.

**Transition to recreational use:** mCPP appeared on the **European illicit drug market around 2004**, initially in France [Ref 7] (Lecompte et al. 2006 [Ref 7]). It was widely misidentified as MDMA and distributed as an ecstasy substitute — a misidentification facilitated by its partial MDMA-like subjective effects and its appearance in ecstasy-sold tablets (Costa Alegre et al. 2025 [Ref 1]; Brunt et al. 2012 [Ref 6]; Logan et al. 2010 [Ref 10]). By 2005, seizures of mCPP as a standalone designer drug were increasing across Europe (Staack et al. 2007 [Ref 9]).

**Regulatory response:** New Zealand was among the first jurisdictions to formally schedule mCPP, placing it in Class C of the Misuse of Drugs Act 1975, effective **April 2008** [Ref 34]. Germany banned it. The UK's **Psychoactive Substances Act 2016** covered mCPP under its blanket prohibition of psychoactive substances not otherwise exempted. As of the 2006 French review, mCPP was not subject to any international regulation (Lecompte et al. 2006 [Ref 7]); no UN Convention scheduling has been identified in any source.

**Forensic note:** mCPP cross-reacts with the commercial Ecstasy EMIT II immunoassay, causing false-positive urine MDMA tests in users of trazodone (as mCPP is its metabolite) and recreational mCPP users (Logan et al. 2010 [Ref 10]).

---

## Subjective Effects

All subjective effects data from human clinical challenge studies — predominantly the intravenous or oral administration of 0.08–0.5 mg/kg in controlled settings. No published controlled recreational dose-escalation study in humans. The dose range associated with recreational use is substantially higher than clinical probe doses.

**Primary reported effects at clinical probe doses (0.08–0.5 mg/kg oral/IV):**

- **Anxiety / anxiogenesis:** The most consistently documented effect. mCPP reliably induces anxiety in healthy volunteers and psychiatric patients (Kahn & Wetzler 1991 [Ref 36]; Pigott et al. 1991 [Ref 13]; Zohar & Insel 1987 [Ref 12]). Mediated by 5-HT₂C.
- **Depersonalization / derealization:** Simeon et al. (1995) [Ref 11] documented depersonalization in 67 subjects (OCD, social phobia, borderline personality disorder, and healthy volunteers), significantly more than placebo; correlated with panic induction but not anxiety, depression, or drowsiness.
- **OCD symptom exacerbation:** mCPP significantly worsened OCD symptoms in patients; low-dose (0.25 mg/kg) was more specific to OCD symptoms; standard dose (0.5 mg/kg) more broadly anxiogenic (Erzegovesi et al. 2001; Zohar & Insel 1987 [Ref 12]).
- **Dysphoria/depression:** mCPP selectively increased POMS depression and tenseness scores in depressed patients (Riedel et al. 2002 [Ref]); OCD patients became significantly more depressed and dysphoric [Ref 12].
- **Neuroendocrine effects:** Consistent, dose-dependent elevation of ACTH, cortisol, prolactin, and growth hormone (Kahn & Wetzler 1991 [Ref 36]; Ghaziuddin et al. 2003 [Ref 20]). Cortisol response mediated by 5-HT₂C; blunted in cocaine addicts and anorexic patients; augmented in seasonal affective disorder.
- **Thermoregulation (biphasic):** IV mCPP (0.08 mg/kg) produced initial hypothermia (−0.04°C at 12 min) followed by progressive hyperthermia (+0.17°C at 90 min), with increased plasma norepinephrine (Schwartz et al. 1995 [Ref 19]).
- **Appetite suppression / food intake reduction:** mCPP (oral) reduced palatable food consumption and BOLD fMRI responses to food images in healthy women via 5-HT₂C-mediated mechanisms (Thomas et al. 2018 [Ref 4]; Thomas et al. 2014 [Ref 5]).
- **Cardiovascular effects:** Mild elevations in systolic and diastolic blood pressure and heart rate at IV doses (Ghaziuddin et al. 2003 [Ref 20]; Seibyl et al. 1991 [Ref 27]).

**Documented at recreational/overdose doses:**
- Visual disturbances (Kovaleva et al. 2008 [Ref 28])
- Flushing (Kovaleva et al. 2008 [Ref 28])
- Tachycardia (Kovaleva et al. 2008 [Ref 28])
- Agitation, drowsiness (Kovaleva et al. 2008 [Ref 28])

**Recreational user reports (non-controlled):** Lecompte et al. (2006) [Ref 7] noted that recreational users described effects "similar to amphetamines" but reported **few positive subjective effects** — consistent with clinical data showing low hedonic/euphoric potential. mCPP **does not exhibit reinforcing effects** (Lecompte et al. 2006 [Ref 7]).

**Special populations:** In cocaine addicts (Buydens-Branchey et al. 1997) and seasonal affective disorder patients, mCPP produced paradoxical "activation-euphoria" states — potentially relevant to recreational use patterns in polydrug users.

**Alcohol craving:** mCPP challenge produced significant increases in alcohol craving in recently detoxified alcoholics via serotonergic mechanisms (Naranjo & Kadlec 1991 [Ref 37]; NCT00605904 [Ref 43]).

**Effect taxonomy assessment (re: seed effects):**
The 18 seed effects lack intensity/frequency values. Based on clinical literature:
- **Anxiety** [feeling]: Strong/very common — the primary documented effect
- **Stimulation** [body]: Mild/common — supported by clinical data
- **Appetite suppression** [body]: Moderate/common — 5-HT₂C mediated, well documented
- **Temperature dysregulation** [body]: Moderate/common — biphasic thermoregulatory effect documented
- **Abnormal heartbeat / vasoconstriction** [body]: Mild-moderate/uncommon — tachycardia and BP elevation documented
- **Headache** [body]: Moderate/common — mentioned in review literature
- **Nausea** [body]: Mild/common — mentioned in general adverse effects
- **Dysphoria** [feeling]: Moderate/common — consistently documented
- **Depression** [feeling]: Mild-moderate/uncommon — documented in depressed patients
- **Depersonalization** [self]: Moderate/uncommon — documented in clinical study
- **Bruxism, increased urination, dehydration sensation**: Low confidence — not specifically documented in clinical studies retrieved; likely inferred from community reports
- **Visual drifting, tracers** [perception]: Low confidence — visual disturbances documented only in overdose context
- **Pupil dilation, sexual arousal suppression** [body]: Not specifically documented in literature retrieved

---

## Safety & Toxicity

### Acute Toxicity

**Documented fatal case:**
Gaillard et al. (2013) [Ref 16] reported the **only published fatal case** linked to mCPP ingestion. A 20-year-old male cocaine addict and regular ecstasy user (with pre-existing allergic asthma) ingested approximately **20 mg mCPP** in a white tablet sold as ecstasy (stamped with a "smiling sun" logo). He developed a severe asthma attack progressing over several hours to fatal cardiorespiratory arrest. mCPP concentration in bile: 5.1 ng/mL; urine: 15.0 ng/mL; absent in hair (confirming first use). The authors concluded death resulted from **asthma attack violently decompensated following mCPP ingestion**. The tablet contained 45.8 mg mCPP per tablet; he ingested half. No other relevant drug levels were reported.

**Clinical significance:** This case establishes **asthma as a critical contraindication** for mCPP exposure, even at low doses. The mechanism likely involves serotonin-mediated bronchoconstriction via 5-HT₂ receptor activation in bronchial smooth muscle. Persons receiving trazodone or nefazodone who have asthma may warrant monitoring.

**Non-fatal overdose:**
Kovaleva et al. (2008) [Ref 28] documented a female patient who ingested three multi-colored tablets (identity sold as ecstasy). She developed anxiety, agitation, drowsiness, flushing, visual disturbances, and tachycardia. Plasma mCPP: 320 ng/mL (approximately 6× the therapeutic trazodone-derived range of 26–108 ng/mL). The patient also had amphetamine (40 ng/mL), benzoylecgonine (47 ng/mL), and alcohol (0.7 g/L) in blood. Symptoms resolved with supportive care. The authors cautioned against attributing all symptoms to mCPP given the polydrug context.

### Neurotoxicity

**mCPP is classified as non-neurotoxic.** Baumann et al. (2014) [Ref 29] demonstrated directly that repeated mCPP administration in rats produces large acute 5-HT elevations (>5-fold) but, unlike fenfluramine/d-fenfluramine, does **not** cause long-term 5-HT depletion at 2 weeks. This was attributed to phenylpiperazines inducing lower SERT-mediated ionic currents than neurotoxic compounds. Gobbi et al. (2002) [Ref 30] confirmed mCPP as a non-neurotoxic SERT substrate, with substantially lower synaptosome-level release than neurotoxic MDMA or pCA.

This distinguishes mCPP importantly from MDMA and fenfluramine in terms of chronic serotonergic risk.

### LD₅₀ / Therapeutic Index

No human LD₅₀ data published. No animal LD₅₀ data retrieved from published sources in this search. **[Gap — flag for editorial]**

### Serotonin Syndrome Risk

mCPP's activity at multiple 5-HT receptor subtypes plus serotonin-releasing properties create significant serotonin syndrome risk when combined with other serotonergic agents (SSRIs, SNRIs, MAOIs, triptans, tramadol). Lecompte et al. (2006) [Ref 7] explicitly flagged serotonin syndrome risk as a key concern. Kast (2009) [Ref 15] argued that chronic mCPP generation from trazodone poses ongoing serotonergic risk. **No published case reports of serotonin syndrome specifically from mCPP alone were identified**, but the pharmacological basis is well-established.

### Trazodone-generated mCPP

An often-overlooked safety consideration: patients receiving therapeutic doses of trazodone (antidepressant), nefazodone, or etoperidone are continuously exposed to mCPP as an active metabolite, via CYP3A4-mediated N-dealkylation (Costa Alegre et al. 2025 [Ref 1]). Kast (2009) [Ref 15] argued that clinically significant mCPP levels are present 24 hours/day in trazodone users and that documented ill effects may outweigh benefits of trazodone given safer alternatives. False-positive urine MDMA testing in trazodone patients is a documented forensic complication (Logan et al. 2010 [Ref 10]).

---

## Harm Reduction

Based on the evidence gathered:

1. **Asthma contraindication:** Any person with reactive airways disease or asthma should avoid mCPP entirely. Even low recreational doses have been fatal in asthmatic individuals (Gaillard et al. 2013 [Ref 16]).

2. **Tablet identification:** mCPP has been found in tablets sold as ecstasy (MDMA). Reagent testing: mCPP does not produce the characteristic Marquis purple/black MDMA reaction; it may produce little or no color change. MDMA test strips would not distinguish mCPP from MDMA if cross-reactive immunoassays are used. Drug checking services are essential.

3. **MDMA urine test:** mCPP causes false-positive results on the Ecstasy EMIT II urine immunoassay (Logan et al. 2010 [Ref 10]). Persons on trazodone may generate positive MDMA urine tests without having taken MDMA.

4. **Serotonin syndrome risk:** Avoid combining mCPP with SSRIs, SNRIs, MAOIs, lithium, tramadol, triptans, or other serotonergic agents. The combination markedly raises serotonin syndrome risk (Lecompte et al. 2006 [Ref 7]).

5. **CYP2D6 inhibitors:** Cocaine, diltiazem, paroxetine, fluoxetine, and other CYP2D6 inhibitors significantly increase mCPP plasma concentrations (Staack et al. 2007 [Ref 9]). This is a plausible mechanism for the "cocaine: lethal" interaction listed in the brief.

6. **Anxiety and psychological risk:** mCPP reliably induces anxiety, panic, and depersonalization. Individuals with pre-existing anxiety disorders, OCD, borderline personality disorder, or psychosis may experience significantly amplified effects. Predisposing psychiatric pathologies are a documented risk factor (Lecompte et al. 2006 [Ref 7]).

7. **Emergency response:** Given the potential for acute severe anxiety, panic, depersonalization, asthma exacerbation, and serotonin syndrome, any suspected mCPP intoxication with respiratory symptoms should be treated as a medical emergency. Supportive care is the primary treatment; 5-HT₂C antagonists (e.g., cyproheptadine) may theoretically help but no specific protocol is published.

---

## Tolerance & Dependence

### Tolerance

No published controlled human study on mCPP tolerance development found. In animal models, the 5-HT₂C receptor undergoes **desensitization** with repeated agonist exposure — a general class effect. Marathon runners (regular aerobic exercise) showed blunted cortisol and prolactin responses to mCPP, interpreted as exercise-induced 5-HT₂C receptor downregulation (Broocks et al. 1999, PMID 9885795 [Ref]). This provides indirect evidence for tolerance development to mCPP's neuroendocrine effects.

### Dependence and Abuse Potential

mCPP has **low abuse/reinforcing potential**. Recreational users report few positive subjective effects (Lecompte et al. 2006 [Ref 7]). The drug does not exhibit reinforcing properties in standard animal or human frameworks. Drug discrimination studies show mCPP's interoceptive cue is not blocked by benzodiazepines (alprazolam), and mCPP's stimulus is distinct from anxiolytic drug classes (Gommans et al. 1999; PMID 10515318 [Ref]).

### Withdrawal

No withdrawal syndrome from mCPP has been documented in published literature. Given the low dependence liability, clinical withdrawal syndrome is not expected. **[Gap]**

---

## Interactions

| Interacting drug | Mechanism | Evidence | Severity assessment |
|---|---|---|---|
| **MDMA** | Pharmacodynamic: both serotonergic; MDMA users show altered (initially blunted, later enhanced) mCPP neuroendocrine responses (McCann et al. 1999 [Ref 14]; Hatzidimitriou et al. 2002 [Ref 33]) | Clinical studies in MDMA users | Dangerous — additive serotonergic effects; combination increases serotonin syndrome risk |
| **Cocaine** | Pharmacokinetic: cocaine inhibits CYP2D6, reducing mCPP hydroxylation → increased mCPP plasma levels (Staack et al. 2007 [Ref 9]); also pharmacodynamic (both stimulant/serotonergic) | Forensic case; one overdose case with cocaine metabolite present | Dangerous — CYP2D6 inhibition raises mCPP exposure; polydrug toxicity documented in overdose context |
| **Tramadol** | Pharmacodynamic: tramadol has serotonergic activity (weak SERT inhibitor/5-HT releaser); combination raises serotonin syndrome risk | Mechanism-based; no published case report found | Plausible dangerous risk — serotonin syndrome mechanism; "lethal" severity in brief is **not confirmed by published cases** — flag for editorial |
| **Alcohol** | Pharmacodynamic: likely additive CNS effects; alcohol present in the only non-fatal overdose case (0.7 g/L) (Kovaleva et al. 2008 [Ref 28]) | Case report context; no controlled study | Unknown severity; CNS additive effects plausible |
| **SSRIs/SNRIs** | Pharmacodynamic: additive serotonergic effects via SERT inhibition + mCPP serotonin release/5-HT₂C agonism | Class-based mechanism; anxiety from acute SSRIs mediated by 5-HT₂C, same as mCPP (Bagdy et al. 2001 [Ref]) | Dangerous — serotonin syndrome risk |
| **Trazodone/nefazodone** | Pharmacokinetic: these drugs are converted to mCPP by CYP3A4; mCPP is the active metabolite (Costa Alegre et al. 2025 [Ref 1]) | Well-established pharmacokinetics | Additive effect — trazodone generates ongoing mCPP exposure |
| **CYP2D6 inhibitors** (paroxetine, fluoxetine, diltiazem) | Pharmacokinetic: inhibit CYP2D6, reducing mCPP hydroxylation → elevated mCPP plasma levels (Staack et al. 2007 [Ref 9]; von Moltke et al. 1999 [Ref 40]) | In vitro and forensic case evidence | Moderate — increased mCPP exposure |

**Interaction flags for editorial review:**
- **"Tramadol: lethal"** (brief) — No published case reports of fatal tramadol-mCPP combination found. The serotonin syndrome mechanism is plausible, and tramadol alone can cause fatal serotonin syndrome when combined with other serotonergic drugs. However, the specific "lethal" severity rating for this combination is not supported by published clinical evidence and should be reviewed.
- **"Cocaine: lethal"** (brief) — CYP2D6 inhibition causing elevated mCPP confirmed. One non-fatal overdose involved cocaine metabolite. The fatality case (Gaillard 2013) did not report cocaine. "Lethal" severity classification needs sourcing review.
- **"Alcohol: unknown"** (brief) — Accurate; the interaction severity is not confirmed. One non-fatal overdose case had alcohol, but polydrug context prevents definitive attribution.

---

## Legal Status

| Jurisdiction | Status | Notes |
|---|---|---|
| **New Zealand** | Class C controlled substance | Misuse of Drugs Act 1975; effective April 2008; possession illegal from October 2008 [Ref 34] |
| **Germany** | Scheduled/banned | Controlled substance; date of scheduling not confirmed by primary source |
| **United Kingdom** | Effectively prohibited | Psychoactive Substances Act 2016 (blanket ban on psychoactive substances not otherwise exempted) [Ref 34] |
| **United States** | Unscheduled federally | Not controlled under federal Controlled Substances Act as of sources retrieved; state laws not assessed |
| **European Union** | Variable by country | No EU-wide scheduling; some member states have national controls; not listed under UN Conventions [Ref 7] |
| **Australia** | Not confirmed | No primary source found; assess via TGA/Poisons Standard |
| **Canada** | Not confirmed | No primary source found |
| **International** | Not scheduled | No UN Convention listing as of Lecompte et al. 2006 [Ref 7]; more recent status not verified |

**Note:** Legal data is drawn from web-retrieved sources and Wikipedia; verification against primary legal databases (EMCDDA, DEA, Home Office) is recommended before publication.

---

## Clinical Trials

| NCT ID | Status | Phase | Condition | Sponsor | Role of mCPP |
|---|---|---|---|---|---|
| NCT00605904 | COMPLETED | Phase 2 | Alcoholism | NIAAA | Pharmacological probe to induce/modulate alcohol craving |
| NCT03962829 | TERMINATED | N/A | Eating behavior, obesity | University of Birmingham | 5-HT₂C agonist probe for cognitive control, appetite, neural responses |

No active or recruiting clinical trials using mCPP were identified. The University of Birmingham trial was terminated (reason not specified in registry). These trials reflect mCPP's research use, not its development as a therapeutic agent in its own right.

---

## Community Feedback Analysis

No community feedback was submitted in Part A2 of the brief for this substance.

---

## Gaps & Flags

### 🚨 Critical Data Errors (Database Corrections Required)

1. **[CRITICAL] Systematic name wrong:** Brief contains "2-(4-chloro-2-methylphenoxy)propanoic acid" = mecoprop (herbicide, CID 7153). Correct value: 1-(3-chlorophenyl)piperazine. Must be corrected before publication.

2. **[CRITICAL] SMILES blank:** Correct SMILES: `ClC1=CC(=CC=C1)N1CCNCC1`

3. **[CRITICAL] PubChem CID blank:** Correct CID: **1355**

4. **[CRITICAL] Molecular formula blank:** Correct: C₁₀H₁₃ClN₂

5. **[CRITICAL] Molecular weight blank:** Correct: 196.67 g/mol

6. **[CRITICAL] InChIKey blank:** Correct: VHFVKMTVMIZMIK-UHFFFAOYSA-N

7. **[CRITICAL] IUPAC blank:** Correct: 1-(3-chlorophenyl)piperazine

### ⚠️ Pharmacological Classification Flags

8. **"Serotonin reuptake inhibitor" is incomplete:** mCPP is primarily a SERT substrate (serotonin releaser). Recommend changing to "Serotonin releasing agent" or "Serotonin transporter substrate." The "reuptake inhibition" framing understates the releasing mechanism and the serotonin syndrome risk.

9. **"Alpha-2 adrenergic receptor antagonist":** Alpha-2 affinity is documented in review literature, but specific Ki and functional classification (agonist vs. antagonist) not confirmed in retrieved primary sources. Recommend editorial verification.

10. **"Stimulant" psychoactive class:** mCPP's dominant psychoactive effects are anxiogenic/dysphoric. It produces hypolocomotion in animals and anxiety/panic in humans — not typical stimulant effects. Some stimulant-like effects documented in polydrug users. Consider reclassifying to "Serotonergic" or "Entactogen" with a note on anxiogenic predominance, or at minimum noting the atypicality.

### ⚠️ Safety-Critical Flags

11. **"Tramadol: lethal" interaction:** No published case reports of fatal tramadol-mCPP combination found. Serotonin syndrome mechanism is plausible. Severity requires primary source citation before retention as "lethal."

12. **"Cocaine: lethal" interaction:** CYP2D6 inhibition mechanism confirmed; polydrug overdose context documented; but no specific fatal case of mCPP + cocaine identified. Severity requires sourcing.

13. **Asthma contraindication not in database:** The fatality was an asthmatic at only ~20mg dose. Asthma should be listed as a contraindication.

14. **Serotonin syndrome risk with SSRIs, triptans, tramadol:** These interactions are not in the current interaction list but are pharmacologically well-supported. Generation agent should propose additions.

### 📋 Data Gaps (No Published Sources Found)

15. **LD₅₀:** No animal or human data found. "Acute: moderate" toxicity rating in brief is inferred from class.

16. **Protein binding:** No published data found.

17. **Tolerance development rate:** No controlled human study. Only indirect evidence (marathon runner study) suggesting 5-HT₂C downregulation.

18. **Withdrawal syndrome:** Not documented in literature.

19. **Physical properties:** No melting point, solubility, or stability data found in published sources.

20. **Controlled human dose-escalation study:** Does not exist in published literature. Recreational dose ranges are community-consensus only (PsychonautWiki), not derived from published pharmacokinetic/pharmacodynamic studies. Dose data confidence level should be noted accordingly.

21. **Legal status (Australia, Canada, EU specific countries):** Not confirmed by primary legal sources.

22. **"Street-name candidates" field is blank in brief:** mCPP has been sold as "Explode," "Legal X," and under various trade names as party pills. Documentation is from grey literature only.

23. **Discovery/synthesis history:** First synthesis in 1951 by Thomas Wicker Jr. is from web-retrieved secondary sources, not a primary reference verified via API tools.