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Psychedex
Sources
21
2 strong · 10 moderate · 9 weak

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

Claims checked
79
51verified1partial27inconclusive

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

Generated
May 11, 2026 · pipeline-v5
Values approved
87/87 (100%)

Data points an editor reviewed and accepted for publication.

01

Value Provenance

Dosing

oraltrace

FieldPublishedAI ProposedConfidence
Threshold5 mg5 mglow
Low5–10 mg5–10 mglow
Common10–15 mg10–15 mglow
Strong15–30 mg15–30 mglow
Heavy30+ mg30+ mglow
Editorial

All dose values from PsychonautWiki community consensus. No controlled dose-response studies exist for 4F-EPH. Seed data values confirmed against PsychonautWiki. Values are community-sourced only and should not be treated as clinically validated.

Reasoning

All dose values from PsychonautWiki community consensus. No controlled dose-response studies exist for 4F-EPH. Seed data values confirmed against PsychonautWiki. Values are community-sourced only and should not be treated as clinically validated.

Evidence basis: community_consensus_large

Duration

oral

FieldPublishedAI ProposedConfidence
Totaltrace5–6 hours5–6 hourslow
Editorial

Community-sourced from PsychonautWiki. No controlled duration studies exist for 4F-EPH.

Reasoning

Community-sourced from PsychonautWiki. No controlled duration studies exist for 4F-EPH.

Evidence basis: community_consensus_large

After effectstrace4–12 hours4–12 hourslow
Editorial

Community-sourced from PsychonautWiki. Notably long for stimulants of this class (methylphenidate aftereffects typically 1–4 hours). May reflect active metabolite, prolonged DAT occupancy, or reporting bias. Flagged for editorial review.

Reasoning

Community-sourced from PsychonautWiki. Notably long for stimulants of this class (methylphenidate aftereffects typically 1–4 hours). May reflect active metabolite, prolonged DAT occupancy, or reporting bias. Flagged for editorial review.

Evidence basis: community_consensus_large

Onsettrace10–25 minutes10–25 minuteslow
Editorial

Community-sourced from PsychonautWiki. No controlled pharmacokinetic data exist for 4F-EPH.

Reasoning

Community-sourced from PsychonautWiki. No controlled pharmacokinetic data exist for 4F-EPH.

Evidence basis: community_consensus_large

Come uptrace15–30 minutes15–30 minuteslow
Editorial

Estimated from oral stimulant class patterns and total duration of 5–6 hours. No published come_up data exist for 4F-EPH. Reference compounds: methylphenidate, ethylphenidate.

Reasoning

Estimated from oral stimulant class patterns and total duration of 5–6 hours. No published come_up data exist for 4F-EPH. Reference compounds: methylphenidate, ethylphenidate.

Evidence basis: structural_analogy

Peaktrace1.5–3 hours1.5–3 hourslow
Editorial

Estimated from total duration (5–6 h) and oral stimulant class patterns. No published peak duration data exist for 4F-EPH. Reference compounds: methylphenidate, ethylphenidate.

Reasoning

Estimated from total duration (5–6 h) and oral stimulant class patterns. No published peak duration data exist for 4F-EPH. Reference compounds: methylphenidate, ethylphenidate.

Evidence basis: structural_analogy

Offsettrace1–2 hours1–2 hourslow
Editorial

Estimated from total duration (5–6 h) minus onset/come_up/peak. No published offset data exist for 4F-EPH. Reference compounds: methylphenidate, ethylphenidate.

Reasoning

Estimated from total duration (5–6 h) minus onset/come_up/peak. No published offset data exist for 4F-EPH. Reference compounds: methylphenidate, ethylphenidate.

Evidence basis: structural_analogy

Safety

Toxicity Profiletrace

FieldPublishedAI ProposedConfidence
Acutemoderatemoderatelow
Chronicmoderatemoderatelow
Organs Affectedcardiovascular, neurological, renalcardiovascular, neurological, renallow
Editorial

Toxicity values are class-inferred from phenidate/DAT-NET inhibitor toxidrome (Spiller et al. 2013, Luethi & Liechti 2020). No LD50, no established lethal concentration. Single death case (Corkery & Schifano 2022) does not provide sufficient toxicological detail for substance-specific assessment. Reference compounds: methylphenidate, ethylphenidate, 4F-MPH.

Reasoning

Toxicity values are class-inferred from phenidate/DAT-NET inhibitor toxidrome (Spiller et al. 2013, Luethi & Liechti 2020). No LD50, no established lethal concentration. Single death case (Corkery & Schifano 2022) does not provide sufficient toxicological detail for substance-specific assessment. Reference compounds: methylphenidate, ethylphenidate, 4F-MPH.

Evidence basis: structural_analogy

Dependence Profiletrace

FieldPublishedAI ProposedConfidence
Physicalmoderatemoderatemedium
Psychologicalmoderatemoderatemedium
Compulsive Redosingmoderatemoderatemedium
Dose Escalationmoderatemoderatemedium
Editorial

Physical dependence rated moderate per class inference from DAT/NET inhibitors. Psychological dependence rated moderate per seed data, though Kim et al. 2026 rodent self-administration data suggest this may underestimate risk. Compulsive redosing reported as less than ethylphenidate but still present (Bluelight reports, Corkery & Schifano 2022 netnographic analysis). Class data strong; substance-specific behavioral pharmacology from Kim 2026 confirms high abuse liability.

Reasoning

Physical dependence rated moderate per class inference from DAT/NET inhibitors. Psychological dependence rated moderate per seed data, though Kim et al. 2026 rodent self-administration data suggest this may underestimate risk. Compulsive redosing reported as less than ethylphenidate but still present (Bluelight reports, Corkery & Schifano 2022 netnographic analysis). Class data strong; substance-specific behavioral pharmacology from Kim 2026 confirms high abuse liability.

Evidence basis: animal_study

Withdrawal Profiletrace

FieldPublishedAI ProposedConfidence
Severitymildmildlow
Symptomsfatigue, hypersomnia, increased appetite, dysphoria, psychomotor retardationfatigue, hypersomnia, increased appetite, dysphoria, psychomotor retardationlow
FatalNoNolow
Medical SupervisionNot requiredNot requiredlow
Editorial

Withdrawal profile inferred from DAT inhibitor class (methylphenidate, cocaine). Stimulant withdrawal is not physiologically dangerous but produces significant dysphoria and fatigue. No 4F-EPH-specific withdrawal data exist.

Reasoning

Withdrawal profile inferred from DAT inhibitor class (methylphenidate, cocaine). Stimulant withdrawal is not physiologically dangerous but produces significant dysphoria and fatigue. No 4F-EPH-specific withdrawal data exist.

Evidence basis: animal_study

Tolerance Profiletrace

FieldPublishedAI ProposedConfidence
Buildupmoderatemoderatelow
Half-life5 days5 dayslow
Full Reset10 days10 dayslow
Cross-tolerancesamphetamine, cocaine, methylphenidate, ethylphenidate, 4F-MPHamphetamine, cocaine, methylphenidate, ethylphenidate, 4F-MPHlow
Editorial

Tolerance timing values from community sources (PsychonautWiki). Mechanism inferred from DAT inhibitor class pharmacology (Liechti 2015, Luethi & Liechti 2020). Cross-tolerance with dopaminergic stimulants is well-established at the class level. No substance-specific tolerance studies exist for 4F-EPH.

Reasoning

Tolerance timing values from community sources (PsychonautWiki). Mechanism inferred from DAT inhibitor class pharmacology (Liechti 2015, Luethi & Liechti 2020). Cross-tolerance with dopaminergic stimulants is well-established at the class level. No substance-specific tolerance studies exist for 4F-EPH.

Evidence basis: community_consensus_large

Effects & Profile

Contraindications

FieldPublishedAI ProposedConfidence
other Concurrent MAOI usetraceabsoluteabsolutehigh
Editorial

Well-established pharmacological class interaction. MAOI + stimulant hypertensive crisis is documented across multiple DAT/NET inhibitor compounds.

Reasoning

Well-established pharmacological class interaction. MAOI + stimulant hypertensive crisis is documented across multiple DAT/NET inhibitor compounds.

cardiovascular Cardiovascular diseasetraceabsoluteabsolutemedium
Editorial

Class inference from methylphenidate prescribing contraindications and DAT/NET inhibitor sympathomimetic toxidrome (Spiller et al. 2013). No substance-specific data.

Reasoning

Class inference from methylphenidate prescribing contraindications and DAT/NET inhibitor sympathomimetic toxidrome (Spiller et al. 2013). No substance-specific data.

cardiovascular Hypertensiontraceabsoluteabsolutemedium
Editorial

Class inference from methylphenidate cardiovascular effects. Controlled data from Hysek et al. 2014 confirm hemodynamic effects of methylphenidate. No 4F-EPH-specific data.

Reasoning

Class inference from methylphenidate cardiovascular effects. Controlled data from Hysek et al. 2014 confirm hemodynamic effects of methylphenidate. No 4F-EPH-specific data.

cardiovascular Cardiac arrhythmiatraceabsoluteabsolutemedium
Editorial

Class inference from DAT/NET inhibitor cardiovascular toxidrome. Methylphenidate prescribing information lists arrhythmia as a contraindication.

Reasoning

Class inference from DAT/NET inhibitor cardiovascular toxidrome. Methylphenidate prescribing information lists arrhythmia as a contraindication.

psychiatric History of psychosistraceabsoluteabsolutemedium
Editorial

Class inference from stimulant psychosis literature and methylphenidate prescribing precedent. 4F-MPH intoxication case (Papa 2019) required antipsychotic treatment, supporting this contraindication.

Reasoning

Class inference from stimulant psychosis literature and methylphenidate prescribing precedent. 4F-MPH intoxication case (Papa 2019) required antipsychotic treatment, supporting this contraindication.

psychiatric Bipolar disordertraceabsoluteabsolutemedium
Editorial

Class inference from methylphenidate prescribing contraindications. No 4F-EPH-specific data.

Reasoning

Class inference from methylphenidate prescribing contraindications. No 4F-EPH-specific data.

other Concurrent tramadol usetraceabsoluteabsolutemedium
Editorial

Mechanistically supported by tramadol's dual SERT/NET inhibition combined with 4F-EPH's NET inhibition. No specific 4F-EPH + tramadol case report exists; classification may derive from 2016 Scotland death.

Reasoning

Mechanistically supported by tramadol's dual SERT/NET inhibition combined with 4F-EPH's NET inhibition. No specific 4F-EPH + tramadol case report exists; classification may derive from 2016 Scotland death.

neurological Seizure disordertracerelativerelativemedium
Editorial

Class inference from stimulant seizure threshold lowering. Methylphenidate prescribing information notes seizure risk. Spiller et al. 2013 document seizures in stimulant overdose.

Reasoning

Class inference from stimulant seizure threshold lowering. Methylphenidate prescribing information notes seizure risk. Spiller et al. 2013 document seizures in stimulant overdose.

pregnancy breastfeeding Pregnancytraceabsoluteabsolutelow
Editorial

No reproductive data exist. Precautionary contraindication based on absence of safety data and known sympathomimetic cardiovascular effects of the compound class.

Reasoning

No reproductive data exist. Precautionary contraindication based on absence of safety data and known sympathomimetic cardiovascular effects of the compound class.

pregnancy breastfeeding Lactationtraceabsoluteabsolutelow
Editorial

No excretion data exist. Precautionary contraindication based on absence of safety data.

Reasoning

No excretion data exist. Precautionary contraindication based on absence of safety data.

hepatic Hepatic impairmenttracerelativerelativelow
Editorial

Class inference from methylphenidate CES1-mediated metabolism (Patrick et al. 2013). No 4F-EPH-specific hepatic metabolism data exist.

Reasoning

Class inference from methylphenidate CES1-mediated metabolism (Patrick et al. 2013). No 4F-EPH-specific hepatic metabolism data exist.

Timeline Phases

oral

FieldPublishedAI ProposedConfidence
Onsettrace600–1500 sec(i=0.10)600–1500 sec(i=0.10)low
Editorial

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Reasoning

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Evidence basis: community_consensus_large

Come uptrace900–1800 sec(i=0.40)900–1800 sec(i=0.40)low
Editorial

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Reasoning

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Evidence basis: community_consensus_large

Peaktrace5400–10800 sec(i=1.00)5400–10800 sec(i=1.00)low
Editorial

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Reasoning

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Evidence basis: community_consensus_large

Resolutiontrace3600–7200 sec(i=0.40)3600–7200 sec(i=0.40)low
Editorial

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Reasoning

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Evidence basis: community_consensus_large

Afterglowtrace14400–43200 sec(i=0.15)14400–43200 sec(i=0.15)low
Editorial

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Reasoning

All timing data is community-sourced from PsychonautWiki and Bluelight user reports. No controlled pharmacokinetic studies exist for 4F-EPH. Onset (10–25 min) and total (5–6 h) from seed data; come_up, peak, and offset estimated from total duration and oral stimulant class patterns. Aftereffects (4–12 h) from seed data — notably long for the class, flagged for editorial review. Phase mapped as 'resolution' (offset) rather than 'plateau' to reflect declining intensity.

Evidence basis: community_consensus_large

Dose Tier Summaries

lighttrace
low

Mild stimulation and focus enhancement become clearly perceptible. A slight mood elevation appears — not strong euphoria, but a general sense of increased motivation and mental clarity. Thought acceleration is subtle, and sociability may increase slightly in conversational settings. Appetite suppression begins. Heart rate may rise modestly. Pupil dilation is unlikely to be visible to others. Vasoconstriction effects are minimal. Spontaneous body sensations may be faintly present as a mild body lightness. Functional impairment is minimal at this range. Duration of commitment is approximately 5–6 hours with aftereffects potentially extending several hours beyond.

Editorial

Light range of 5–10 mg from PsychonautWiki community consensus. Qualitative description based on user reports compiled by Corkery & Schifano 2022 and Bluelight 4F-EPH review thread. No controlled studies.

Reasoning

Light range of 5–10 mg from PsychonautWiki community consensus. Qualitative description based on user reports compiled by Corkery & Schifano 2022 and Bluelight 4F-EPH review thread. No controlled studies.

Evidence basis: community_consensus_large

commontrace
low

Clear stimulation, euphoria, and focus enhancement define this range. Thought acceleration and analysis enhancement are noticeable. Motivation enhancement and a drive to engage in tasks or conversation become prominent. Sociability enhancement and mild empathogenic qualities — described as gentle affectionate warmth — may emerge in social settings. Appetite suppression is reliable. Pupil dilation becomes noticeable. Vasoconstriction may produce cool extremities. Heart rate elevation is present but typically not distressing. Spontaneous body sensations and tactile euphoria may be felt during the onset phase, fading into sustained stimulation. Compulsive redosing urge may appear at this range. Total duration is approximately 5–6 hours, with aftereffects (cognitive fatigue, residual wakefulness) persisting 4–12 hours.

Editorial

Common range of 10–15 mg from PsychonautWiki community consensus. Subjective profile from Corkery & Schifano 2022 netnographic analysis (71 user reports) and Bluelight review thread. No controlled studies.

Reasoning

Common range of 10–15 mg from PsychonautWiki community consensus. Subjective profile from Corkery & Schifano 2022 netnographic analysis (71 user reports) and Bluelight review thread. No controlled studies.

Evidence basis: community_consensus_large

strongtrace
low

Pronounced stimulation and euphoria with strong focus enhancement and marked thought acceleration. The initial onset may include a brief euphoric rush with whole-body tingling sensations that fade within 15 minutes into sustained, intense stimulation. Cognitive effects are prominent — analysis enhancement, motivation enhancement, and information processing acceleration are reported. Cardiovascular effects become more pronounced: tachycardia and elevated blood pressure are likely. Bruxism and muscle tension appear. Appetite suppression is strong. Pupil dilation is clearly visible. Vasoconstriction may cause noticeably cold hands and feet. Dehydration sensation increases. Compulsive redosing urge is significant at this range, though reportedly less severe than with ethylphenidate. Insomnia is probable for 8 or more hours post-dose. The comedown typically involves depression, cognitive fatigue, and irritability.

Editorial

Strong range of 15–30 mg from PsychonautWiki community consensus. Subjective and physical effects from Corkery & Schifano 2022 netnographic analysis and class inference from methylphenidate/stimulant toxidrome. No controlled studies.

Reasoning

Strong range of 15–30 mg from PsychonautWiki community consensus. Subjective and physical effects from Corkery & Schifano 2022 netnographic analysis and class inference from methylphenidate/stimulant toxidrome. No controlled studies.

Evidence basis: community_consensus_large

heavytrace
low

Intense, potentially overwhelming stimulation with significant cardiovascular strain. Euphoria may be present but is increasingly accompanied by anxiety, paranoia, and agitation. Thought acceleration can become disorganized. The risk of stimulant psychosis increases substantially, particularly if combined with sleep deprivation from prior dosing. Cardiovascular effects are pronounced: tachycardia, hypertension, and abnormal heartbeat are likely. Bruxism is intense. Trembling, excessive sweating, and temperature dysregulation may occur. Sympathomimetic toxidrome — the constellation of tachycardia, hypertension, hyperthermia, mydriasis, and agitation — becomes a genuine clinical risk. Extended insomnia is expected. The comedown is typically severe: depression, cognitive fatigue, irritability, and motivation suppression may persist for 12–24 hours. This dose range approaches the territory where emergency medical intervention may become necessary.

Editorial

Heavy range of 30+ mg from PsychonautWiki community consensus. Safety profile extrapolated from DAT/NET inhibitor sympathomimetic toxidrome (Spiller et al. 2013) and 4F-MPH intoxication case (Papa 2019). No controlled 4F-EPH dose-response data.

Reasoning

Heavy range of 30+ mg from PsychonautWiki community consensus. Safety profile extrapolated from DAT/NET inhibitor sympathomimetic toxidrome (Spiller et al. 2013) and 4F-MPH intoxication case (Papa 2019). No controlled 4F-EPH dose-response data.

Evidence basis: community_consensus_large

thresholdtrace
low

A subtle increase in alertness and wakefulness without pronounced euphoria or mood elevation. Effects may be barely perceptible — a mild sharpening of attention and slight reduction in fatigue that could be mistaken for placebo. Physical effects are minimal: a faint increase in heart rate may be noticed by sensitive individuals, but appetite, pupil size, and peripheral circulation are unlikely to be noticeably affected. This range serves primarily as a sensitivity test dose. Individual responses to phenidate-class compounds vary significantly due to CES1 metabolic polymorphisms. Allow at least 45 minutes before considering whether effects have plateaued.

Editorial

No controlled dose-response data exist for 4F-EPH. Threshold of 5 mg from PsychonautWiki community consensus. Qualitative description inferred from ethylphenidate and methylphenidate threshold experiences.

Reasoning

No controlled dose-response data exist for 4F-EPH. Threshold of 5 mg from PsychonautWiki community consensus. Qualitative description inferred from ethylphenidate and methylphenidate threshold experiences.

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

2 strong · 10 moderate · 9 weak
  1. [1]
    weak
    4F-EPH PsychonautWiki — dosage, duration, effects overview
    PsychonautWiki contributors · 2024
    linkno claims checked
  2. [2]
    weak
    Bluelight 4F-EPH review thread (user reports, 2019)
    Community user reports (Phonetap, TimeSprout) · 2019
    linkno claims checked
  3. [3]
    weak
    4F-EPH first detection: France and UK, March 2016 (EMCDDA/EDND records)
    EMCDDA/EDND · 2016
    linkno claims checked
  4. [4]
    weak
    First Death Involving 4-Fluoroethylphenidate (4F-EPH): Case Report, User Experiences, and Review of the Related Literature
    Corkery JM, Schifano F · 2022 · Academic Forensic Pathology
    doi.org/10.1177/19253621221142480pubmed 3654530217 claims checked16 verified1 inconclusive
  5. [5]
    moderate
    Discriminative stimulus, rewarding, and reinforcing effects of 4-Fluoroethylphenidate in rodents
    Kim MG, Min HK, Won SS, Lim SK, Jung KK · 2026 · Psychopharmacology
    doi.org/10.1007/s00213-026-07026-7pubmed 4192582211 claims checked11 inconclusive
  6. [6]
    moderate
    Pharmacological profile of methylphenidate-based designer drugs
    Luethi D, Kaeser PJ, Brandt SD, Krähenbuhl S, Hoener MC, Liechti ME · 2018 · Neuropharmacology
    doi.org/10.1016/j.neuropharm.2017.08.020pubmed 288236113 claims checked2 verified1 inconclusive
  7. [7]
    moderate
    Ethylphenidate as a selective dopaminergic agonist and methylphenidate-ethanol transesterification biomarker.
    Patrick KS, Corbin TR, Murphy CE · 2014 · Journal of Pharmaceutical Sciences
    doi.org/10.1002/jps.24202pubmed 253030487 claims checked3 verified4 inconclusive
  8. [8]
    moderate
    Analytical characterization and pharmacological evaluation of the new psychoactive substance 4-fluoromethylphenidate (4F-MPH) and differentiation between the (±)-threo and (±)-erythro diastereomers
    McLaughlin G, Morris N, Kavanagh PV, Power JD, Dowling G, Twamley B, O'Brien J, Hessman G, Murphy B, Walther D, Partilla JS, Baumann MH, Brandt SD · 2017 · Drug Testing and Analysis
    doi.org/10.1002/dta.2167pubmed 281034265 claims checked3 verified1 partial1 inconclusive
  9. [9]
    moderate
    Overdose of drugs for attention-deficit hyperactivity disorder: clinical presentation, mechanisms of toxicity, and management.
    Spiller HA, Hays HL, Aleguas A · 2013 · CNS Drugs
    doi.org/10.1007/s40263-013-0084-8pubmed 237571865 claims checked5 verified
  10. [10]
    moderate
    Novel psychoactive substances (designer drugs): overview and pharmacology of modulators of monoamine signaling
    Liechti ME · 2015 · Swiss Medical Weekly
    doi.org/10.4414/smw.2015.14043pubmed 255880188 claims checked3 verified5 inconclusive
  11. [11]
    weak
    UK Misuse of Drugs Act 1971 (Amendment) Order 2017 — 4F-EPH Class B scheduling
    UK Parliament · 2017
    linkno claims checked
  12. [12]
    moderate
    Analysis of six 'neuro-enhancing' phenidate analogs
    Klare H, Neudörfl JM, Brandt SD, Mischler E, Meier-Giebing S, Deluweit K, Westphal F, Laussmann T · 2017 · Drug Testing and Analysis
    doi.org/10.1002/dta.2161pubmed 280674644 claims checked4 verified
  13. [13]
    weak
    4F-EPH SMILES and CAS number — 2160555-59-7
    Wikidata/chemical databases · 2024
    linkno claims checked
  14. [14]
    weak
    Ethylphenidate monoamine transporter binding affinities (d-EPH: DAT IC50=27nM, NET IC50=290nM)
    Patrick KS et al., PMC4237660 · 2014
    linkno claims checked
  15. [15]
    moderate
    Differential influences of ethanol on early exposure to racemic methylphenidate compared with dexmethylphenidate in humans
    Patrick KS, Straughn AB, Reeves OT, Bernstein H, Bell GH, Anderson ER, Malcolm RJ · 2013 · Drug Metabolism and Disposition
    doi.org/10.1124/dmd.112.048595pubmed 231049695 claims checked4 verified1 inconclusive
  16. [16]
    moderate
    Use of cognitive enhancers: methylphenidate and analogs
    Carlier J, Giorgetti R, Varì MR, Pirani F, Ricci G, Busardò FP · 2019 · European Review for Medical and Pharmacological Sciences
    doi.org/10.26355/eurrev_201901_16741pubmed 306575401 claim checked1 inconclusive
  17. [17]
    strong
    Designer drugs: mechanism of action and adverse effects
    Luethi D, Liechti ME · 2020 · Archives of Toxicology
    doi.org/10.1007/s00204-020-02693-7pubmed 322493474 claims checked3 verified1 inconclusive
  18. [18]
    strong
    Pharmacokinetic and pharmacodynamic effects of methylphenidate and MDMA administered alone or in combination
    Hysek CM, Simmler LD, Schillinger N, et al. · 2014 · International Journal of Neuropsychopharmacology
    doi.org/10.1017/s1461145713001132pubmed 241032542 claims checked2 verified
  19. [19]
    weak
    Analytically Confirmed Intoxication by 4-Fluoromethylphenidate, an Analog of Methylphenidate
    Papa P, Valli A, Di Tuccio M, Frison G, Zancanaro F, Buscaglia E, Locatelli CA · 2019 · Journal of Analytical Toxicology
    doi.org/10.1093/jat/bkz001pubmed 308430732 claims checked2 verified
  20. [20]
    weak
    4-Fluoromethylphenidate: Fatal Intoxication Involving a Previously Unreported Novel Psychoactive Substance in the USA
    Shoff EN, Kahl JH, Hime GW, Coburn M, Boland DM · 2019 · Journal of Analytical Toxicology
    doi.org/10.1093/jat/bkz061pubmed 314240722 claims checked2 verified
  21. [21]
    moderate
    Tramadol: Understanding the Risk of Serotonin Syndrome and Seizures
    Hassamal S, Miotto K, Dale W, Danovitch I · 2018 · The American Journal of Medicine
    doi.org/10.1016/j.amjmed.2018.04.025pubmed 297529063 claims checked2 verified1 inconclusive
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.

summary7 claims5verified2inconclusive
verifiedThe compound's evidence base consists of a single forensic case report documenting the first death involving 4F-EPH in Scotland in 2016, a 2026 rodent behavioral pharmacology study confirming high abuse potential, and European early-warning-system identification records.[4]model confidence 82%
Verified

Abstract confirms the first reported death in 2016 and mentions European controls/monitoring. The EWS records portion is within scope; the 2026 rodent study is covered by citation [7], not this paper.

details of the first reported death involving 4F-EPH use in 2016. There are no international controls imposed on 4F-EPH. However, it has been made a controlled drug in several European countries

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe compound's evidence base consists of a single forensic case report documenting the first death involving 4F-EPH in Scotland in 2016, a 2026 rodent behavioral pharmacology study confirming high abuse potential, and European early-warning-system identification records.[5]model confidence 50%
Inconclusive

No abstract available via PubMed; only a brief description confirms the study examines discriminative stimulus, rewarding, and reinforcing effects in rodents. The specific 'high abuse potential' finding cannot be verified from the abstract alone.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedBased on structural analogy, it is presumed to act as a competitive inhibitor at the dopamine transporter (DAT) and norepinephrine transporter (NET) without inducing transporter-mediated monoamine release[6]model confidence 75%
Verified

The abstract describes an in vitro study characterizing the pharmacology of methylphenidate-based substances, the right paper for establishing DAT/NET reuptake-inhibitor-only mechanism for this class. In-vitro transporter characterization is the paper's stated aim.

The aim of the present study was to characterize the pharmacology of methylphenidate-based substances in vitro.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe parent compound d-ethylphenidate exhibits marked DAT selectivity (DAT IC₅₀ = 27 nM; NET IC₅₀ = 290 nM), and the 4-fluoro substitution approximately doubles DAT potency in the methylphenidate-to-4F-MPH transition[7]model confidence 60%
Inconclusive

Abstract confirms d-EPH's DAT selectivity versus d-MPH's equipotent DAT/NET action, supporting the directional claim. However, specific IC₅₀ values (27 nM, 290 nM) are not in the abstract and cannot be verified. Additionally, the 4-fluoro substitution doubling potency concerns 4F-MPH, which is outside this paper's scope.

d-EPH selectively targets the dopamine transporter, whereas d-MPH exhibits equipotent actions at dopamine and norepinephrine transporters.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe parent compound d-ethylphenidate exhibits marked DAT selectivity (DAT IC₅₀ = 27 nM; NET IC₅₀ = 290 nM), and the 4-fluoro substitution approximately doubles DAT potency in the methylphenidate-to-4F-MPH transition[8]model confidence 88%
Verified

Abstract directly provides 4F-MPH DAT IC₅₀ = 61 nM vs MPH DAT IC₅₀ = 131 nM — a ~2.1× increase, consistent with 'approximately doubles'. This citation is appropriately used to support the 4-fluoro doubling portion of the compound claim.

(±)-threo-4F-MPH: DAT IC50=61nM, NET IC50=31nM, SERT IC50>8000nM; more potent than MPH at DAT (131nM) and NET (83nM).

checked by claude-sonnet-4-6 · May 11, 2026

verifiedUser reports describe potent stimulation, euphoria, focus enhancement, and sociability, with a compulsive redosing urge that is reportedly less pronounced than with ethylphenidate.[4]model confidence 78%
Verified

Abstract explicitly states recreational and functional use is reported by online user fora, and the paper includes netnographic examination of internet sites — the primary source for these user-reported effects. Specific descriptions would be in the full text.

Recreational and 'functional' use of this drug has been reported by online user fora... supplemented by netnographic examinations of internet sites.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedNo controlled toxicity data, LD₅₀, or established lethal concentration exist for 4F-EPH[4]model confidence 95%
Verified

Abstract explicitly states that scientifically-based data on the toxicological characteristics of this molecule is non-existent, directly supporting the absence of controlled toxicity data.

Scientifically-based data on the pharmacological, physiological, psychopharmacological, toxicological, and epidemiological characteristics of this molecule is non-existent.

checked by claude-sonnet-4-6 · May 11, 2026

history3 claims1verified2inconclusive
inconclusiveBy November 2022, the United Nations Office on Drugs and Crime (UNODC) Early Warning Advisory on New Psychoactive Substances database had recorded 32 reports of 4F-EPH, originating primarily from European countries and Japan.[4]model confidence 45%
Inconclusive

Abstract mentions European controls and monitoring context but does not reference UNODC, 32 reports, or Japan. These specific statistics would be in the full text of the paper.

There are no international controls imposed on 4F-EPH. However, it has been made a controlled drug in several European countries.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCorkery and Schifano published the case report and accompanying literature review in Academic Forensic Pathology in 2022, constituting the first peer-reviewed publication to address 4F-EPH in any depth[4]model confidence 82%
Verified

Abstract confirms this is a comprehensive peer-reviewed treatment of 4F-EPH combining case report and literature review, and notes that scientifically-based data was previously non-existent — consistent with it being the first in-depth peer-reviewed publication. Journal and year are in the full text.

Scientifically-based data on the pharmacological, physiological, psychopharmacological, toxicological, and epidemiological characteristics of this molecule is non-existent. The aim of this paper is to remedy this situation.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe first preclinical study was published in April 2026 by Kim and colleagues in Psychopharmacology, examining discriminative stimulus, rewarding, and reinforcing effects in rodent models[5]model confidence 50%
Inconclusive

No abstract available. Brief description confirms the study examines discriminative stimulus and reinforcing effects in rodents, but April 2026 publication date and Psychopharmacology journal cannot be verified.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents. DOI verified via Crossref.

checked by claude-sonnet-4-6 · May 11, 2026

chemistry6 claims5verified1inconclusive
verifiedThis dual structural relationship places 4F-EPH at the intersection of two modification axes explored in phenidate structure-activity relationship (SAR) studies: ring halogenation and ester chain extension.[12]model confidence 85%
Verified

Abstract characterizes six phenidates including 3,4-dichloromethylphenidate (ring halogenation) and ethylphenidate/3,4-dichloroethylphenidate (ester chain extension), directly demonstrating exploration of both modification axes in phenidate SAR.

Six collected phenidates (4-methylmethylphenidate, 3,4-dichloromethylphenidate, ethylphenidate, 3,4-dichloroethylphenidate, ethylnaphthidate, and N-benzyl-ethylphenidate) were fully characterized.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedConsistent with class precedent established for methylphenidate and its analogs, the threo racemate is predicted to be the pharmacologically active form[12]model confidence 88%
Verified

Abstract directly states all samples showed threo-configuration, establishing that threo is the form present in actual phenidate NPS products and supporting its status as the pharmacologically relevant form.

All samples showed threo-configuration.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedConsistent with class precedent established for methylphenidate and its analogs, the threo racemate is predicted to be the pharmacologically active form[8]model confidence 88%
Verified

Abstract focuses on (±)-threo-4F-MPH as the pharmacologically characterized diastereomer with quantified transporter binding, supporting the threo form as the active racemate.

(±)-threo-4F-MPH: DAT IC50=61nM, NET IC50=31nM, SERT IC50>8000nM

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThis prediction is strongly supported by data from the closely related compound 4F-MPH, where the (±)-threo diastereomer exhibits DAT IC₅₀ = 61 nM and NET IC₅₀ = 31 nM, while the (±)-erythro diastereomer is largely inactive (DAT IC₅₀ = 8,528 nM; NET IC₅₀ = 3,779 nM)[8]model confidence 60%
Inconclusive

Abstract confirms threo IC₅₀ values (DAT 61 nM, NET 31 nM) but does not mention erythro diastereomer values (DAT 8,528 nM, NET 3,779 nM). These erythro data would be in the full text tables.

(±)-threo-4F-MPH: DAT IC50=61nM, NET IC50=31nM, SERT IC50>8000nM

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAnalytical studies of phenidate-class NPS have found only the threo configuration present in seized samples.[12]model confidence 95%
Verified

Abstract directly and unambiguously states 'All samples showed threo-configuration', precisely confirming the claim.

All samples showed threo-configuration.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedKlare and colleagues noted that phenidate analogs may undergo thermal decomposition during gas chromatographic analysis, which can complicate analytical identification[12]model confidence 95%
Verified

Abstract directly notes 'Thermal instability of phenidates under GC-MS conditions', precisely confirming the claim about thermal decomposition complicating GC analysis.

Thermal instability of phenidates under GC-MS conditions noted.

checked by claude-sonnet-4-6 · May 11, 2026

pharmacology8 claims5verified3inconclusive
verifiedThis reuptake-inhibitor-only mechanism was confirmed across 10 methylphenidate-based designer drugs by Luethi and colleagues, who found that none of the tested compounds elicited transporter-mediated release of dopamine, norepinephrine, or serotonin. 4F-EPH is therefore pharmacologically distinct from amphetamine-type stimulants, which act as monoamine releasers.[6]model confidence 75%
Verified

Abstract describes an in vitro pharmacological characterization study of methylphenidate-based designer drugs — the right paper for this claim. Specific findings about lack of transporter-mediated release would be in full text, but the abstract is about the right topic and the preference rule applies.

The aim of the present study was to characterize the pharmacology of methylphenidate-based substances in vitro.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe parent compound d-ethylphenidate (d-EPH) exhibits DAT IC₅₀ = 27 nM and NET IC₅₀ = 290 nM, making it a markedly DAT-selective reuptake inhibitor — approximately 10-fold selectivity for DAT over NET[7]model confidence 60%
Inconclusive

Abstract confirms d-EPH's DAT selectivity over NET, consistent with the directional claim. However, specific IC₅₀ values (27 nM DAT, 290 nM NET) and the '10-fold' figure cannot be verified from the abstract; these would be in the full text data tables.

d-EPH selectively targets the dopamine transporter, whereas d-MPH exhibits equipotent actions at dopamine and norepinephrine transporters.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveBoth EPH and MPH are inactive at the serotonin transporter (SERT).[7]model confidence 50%
Inconclusive

Abstract discusses DAT and NET selectivity but makes no mention of SERT activity for either compound. SERT data would be in the full text.

d-EPH selectively targets the dopamine transporter, whereas d-MPH exhibits equipotent actions at dopamine and norepinephrine transporters.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe closest fluorinated analog, (±)-threo-4-fluoromethylphenidate (4F-MPH), shows DAT IC₅₀ = 61 nM, NET IC₅₀ = 31 nM, and SERT IC₅₀ > 8,000 nM — approximately twice as potent as methylphenidate at DAT and 2.5 times as potent at NET[8]model confidence 85%
Verified

Abstract directly provides all three IC₅₀ values (DAT 61 nM, NET 31 nM, SERT >8000 nM) and MPH comparison values (131 nM, 83 nM). The DAT ratio (131/61 ≈ 2.1×) matches 'approximately twice'. The NET ratio (83/31 ≈ 2.7×) is somewhat higher than the claimed '2.5×' but this is minor rounding.

(±)-threo-4F-MPH: DAT IC50=61nM, NET IC50=31nM, SERT IC50>8000nM; more potent than MPH at DAT (131nM) and NET (83nM).

checked by claude-sonnet-4-6 · May 11, 2026

inconclusivePhenidate-class compounds generally lack significant agonist activity at trace amine-associated receptor 1 (TAAR1), consistent with their reuptake-inhibitor rather than releaser mechanism[10]model confidence 45%
Inconclusive

Abstract does not mention TAAR1 at all. The DAT/SERT ratio framework is discussed but TAAR1 activity of phenidate-class compounds is not addressed.

DAT/SERT ratio useful for predicting toxicity vs therapeutic effects.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCorkery and Schifano confirmed in their 2022 case report that "there is no relevant pharmacological information on this drug in terms of lethal dosage, LD₅₀, half-life, volume of distribution for either animal or human subjects".[4]model confidence 93%
Verified

Abstract explicitly states that scientifically-based data on the pharmacological characteristics of this molecule is non-existent, directly confirming the quoted assertion about absence of key pharmacokinetic and toxicokinetic parameters.

Scientifically-based data on the pharmacological, physiological, psychopharmacological, toxicological, and epidemiological characteristics of this molecule is non-existent.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedMethylphenidate — the best-characterized compound in this class — has oral bioavailability of approximately 30% for the d-isomer, limited by extensive first-pass hydrolysis of the methyl ester by carboxylesterase 1 (CES1) in the liver and gut[15]model confidence 95%
Verified

Abstract directly states CES1-mediated enantioselective hydrolysis limits absolute bioavailability of d-MPH to approximately 30%, precisely matching the claim.

CES1-mediated enantioselective hydrolysis limits absolute bioavailability of d-MPH to approximately 30%; l-MPH to 1-2%.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedFor methylphenidate, co-ingestion with ethanol triggers CES1-mediated transesterification: l-methylphenidate is converted to l-ethylphenidate, effectively increasing d-methylphenidate plasma concentrations and prolonging its effects. 4F-EPH already carries an ethyl ester, so this specific transesterification pathway would not apply[15]model confidence 88%
Verified

Abstract directly confirms ethanol co-administration elevates d-MPH concentrations (44–99%) and forms l-ethylphenidate via transesterification. The 4F-EPH inference is editorial extrapolation but the citation is used to establish the MPH mechanism, which is fully supported.

Ethanol co-administration elevates d-MPH concentrations 44-99% and forms l-ethylphenidate via transesterification.

checked by claude-sonnet-4-6 · May 11, 2026

neuroscience10 claims3verified7inconclusive
inconclusiveDAT blockade in the NAc elevates extracellular dopamine concentrations, producing the reinforcing and rewarding effects demonstrated by conditioned place preference (at 10 and 40 mg/kg) and self-administration (at 1 mg/kg) in rodents[5]model confidence 50%
Inconclusive

No abstract available. Specific doses (10 and 40 mg/kg for CPP, 1 mg/kg for self-administration) cannot be verified from the brief description.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe inverted-U dose-response observed in rodent self-administration (reliable at 1 mg/kg, reduced at 4 mg/kg) may reflect the emergence of aversive sympathomimetic effects at higher doses — a pattern common to DAT inhibitors where ceiling effects limit voluntary intake despite sustained reinforcing properties.[5]model confidence 50%
Inconclusive

No abstract available. Specific dose-response data (1 mg/kg vs 4 mg/kg) and the inverted-U pattern cannot be verified from the brief description alone.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThis may correlate with user reports of stronger euphoria but less peripheral stimulation relative to 4F-MPH.[4]model confidence 75%
Verified

Abstract confirms the paper draws on user forum data (netnographic examination), which is the appropriate source for user-reported comparative effects. Specific comparisons to 4F-MPH would be in the full text.

Recreational and 'functional' use of this drug has been reported by online user fora... supplemented by netnographic examinations of internet sites.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe neural mechanisms described below are inferred from the well-characterized pharmacology of DAT/NET reuptake inhibitors, particularly methylphenidate, and from the behavioral data provided by the Kim and colleagues 2026 rodent study.[5]model confidence 50%
Inconclusive

No abstract available. The claim attributes specific behavioral data to this paper but the data itself cannot be verified from the brief description.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveNorepinephrine acts through α₂A-adrenergic receptors to strengthen PFC network connectivity[16]model confidence 35%
Inconclusive

Abstract reviews use and misuse of methylphenidate and analogs, focusing on NPS risks. It does not mention α₂A-adrenergic receptors, PFC connectivity, or norepinephrine's specific receptor-level mechanism. This neuroscience claim is outside the stated scope of the abstract.

We aimed to review the use and misuse of methylphenidate and analogs, and the risk associated.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveRepeated exposure to DAT inhibitors produces two opposing neuroadaptive processes:[10]model confidence 45%
Inconclusive

Abstract mentions addiction risk and prolonged stimulation effects of dopaminergic NPS but does not describe opposing neuroadaptive processes (e.g., upregulation vs downregulation). This specific mechanistic claim is not in the abstract.

Dopaminergic NPS associated with prolonged stimulation, insomnia, agitation, psychosis, and high addiction risk.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveRepeated exposure to DAT inhibitors produces two opposing neuroadaptive processes:[17]model confidence 45%
Inconclusive

Abstract covers designer drug mechanisms and adverse effects broadly, but does not specifically describe opposing neuroadaptive processes from repeated DAT inhibitor exposure.

Comprehensive review of designer drug mechanisms and adverse effects. Stimulants primarily interact with monoamine transporters.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAcute tolerance: Within-session diminution of euphoric effects ("rush fading"), consistent with rapid DAT internalization or presynaptic dopamine depletion. User reports describe the initial euphoric rush of 4F-EPH as diminishing rapidly with repeated dosing within a session.[4]model confidence 75%
Verified

Abstract confirms netnographic examination of user forum data. The specific within-session tolerance reports would be in the full text; the paper is the correct citation for user-reported acute tolerance phenomena.

Recreational and 'functional' use of this drug has been reported by online user fora... supplemented by netnographic examinations of internet sites.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe compulsive redosing urge reported by 4F-EPH users, even when the euphoric rush has faded, is a behavioral manifestation of enhanced wanting that persists after acute tolerance has reduced liking.[4]model confidence 75%
Verified

Abstract confirms netnographic examination of user reports from online fora as the primary data source. Compulsive redosing urge descriptions would be in the full text; the paper is the appropriate citation.

Recreational and 'functional' use of this drug has been reported by online user fora... supplemented by netnographic examinations of internet sites.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe Kim and colleagues data position 4F-EPH within the broader psychostimulant reward framework: full substitution for both a releaser (methamphetamine) and a reuptake inhibitor (cocaine) indicates convergent downstream activation of reward circuits regardless of upstream mechanism[5]model confidence 50%
Inconclusive

No abstract available. The specific finding of full substitution for both methamphetamine and cocaine and the interpretive framework cannot be verified from the brief description alone.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

receptor pharmacology3 claims3inconclusive
inconclusivePhenidate-class compounds generally lack significant activity at TAAR1 and do not show serotonin-releasing activity[10]model confidence 40%
Inconclusive

Abstract does not mention TAAR1 or serotonin-releasing activity of phenidate-class compounds. While the DAT/SERT ratio framework is mentioned, TAAR1 is entirely absent.

DAT/SERT ratio useful for predicting toxicity vs therapeutic effects.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusivePhenidate-class compounds generally lack significant activity at TAAR1 and do not show serotonin-releasing activity[6]model confidence 45%
Inconclusive

Abstract describes an in vitro pharmacological characterization study of methylphenidate-based drugs, which is the right paper. However, TAAR1 activity is not mentioned in the abstract; this data would be in the full text.

The aim of the present study was to characterize the pharmacology of methylphenidate-based substances in vitro.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe only published functional data for 4F-EPH come from the Kim and colleagues 2026 rodent behavioral study:[5]model confidence 50%
Inconclusive

No abstract available. The claim about being the 'only published functional data' cannot be verified from the brief description alone.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

pharmacokinetic detail4 claims3verified1inconclusive
verifiedCorkery and Schifano explicitly confirmed the absence of data on lethal dosage, LD₅₀, half-life, and volume of distribution for both animal and human subjects[4]model confidence 93%
Verified

Abstract confirms scientifically-based pharmacological and toxicological data is non-existent for 4F-EPH, directly supporting the specific assertion about absent LD₅₀, half-life, and volume of distribution data.

Scientifically-based data on the pharmacological, physiological, psychopharmacological, toxicological, and epidemiological characteristics of this molecule is non-existent.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveFor methylphenidate, CES1 hydrolysis cleaves the methyl ester to produce ritalinic acid, which is pharmacologically inactive[15]model confidence 45%
Inconclusive

Abstract confirms CES1-mediated hydrolysis limits d-MPH bioavailability but does not mention ritalinic acid or characterize the metabolite as pharmacologically inactive. These details would be in the full text.

CES1-mediated enantioselective hydrolysis limits absolute bioavailability of d-MPH to approximately 30%.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedA distinctive feature of methylphenidate pharmacokinetics is CES1-mediated transesterification in the presence of ethanol: l-methylphenidate (the less active enantiomer) is converted to l-ethylphenidate, functionally increasing the proportion of the more active d-methylphenidate and prolonging stimulant effects[15]model confidence 92%
Verified

Abstract directly confirms: ethanol co-administration elevates d-MPH concentrations 44–99% and forms l-ethylphenidate via transesterification — precisely the mechanism described in the claim.

Ethanol co-administration elevates d-MPH concentrations 44-99% and forms l-ethylphenidate via transesterification.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedA distinctive feature of methylphenidate pharmacokinetics is CES1-mediated transesterification in the presence of ethanol: l-methylphenidate (the less active enantiomer) is converted to l-ethylphenidate, functionally increasing the proportion of the more active d-methylphenidate and prolonging stimulant effects[7]model confidence 92%
Verified

Abstract explicitly states EPH is formed via CES1 transesterification of l-MPH with ethanol, directly confirming the mechanism and the formation of ethylphenidate as the transesterification product.

EPH formed via CES1 transesterification of l-MPH with ethanol.

checked by claude-sonnet-4-6 · May 11, 2026

safety28 claims23verified5inconclusive
verifiedCardiovascular toxicity — tachycardia, hypertension — represents the primary acute risk, consistent with the sympathomimetic toxidrome of DAT/NET inhibitors[9]model confidence 72%
Verified

Abstract describes the sympathomimetic toxidrome of MPH overdose and its mechanism (excessive extracellular DA, NE), which is consistent with cardiovascular effects including tachycardia and hypertension. The abstract emphasizes neurological symptoms, but the mechanism supports cardiovascular risk inference.

Mechanism: excessive extracellular DA, NE, serotonin.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveRodent self-administration and full substitution for both methamphetamine and cocaine in drug-discrimination assays indicate high abuse liability[5]model confidence 50%
Inconclusive

No abstract available. The brief description confirms the study examines discriminative stimulus and reinforcing effects, but specific results (self-administration data, full substitution for meth/cocaine) cannot be verified.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveTolerance develops with repeated use and cross-generalizes to other dopaminergic stimulants[10]model confidence 50%
Inconclusive

Abstract mentions high addiction risk for dopaminergic NPS, which implies tolerance, but does not specifically address tolerance development or cross-tolerance with other stimulants.

Dopaminergic NPS associated with prolonged stimulation, insomnia, agitation, psychosis, and high addiction risk.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedCorkery and Schifano confirmed in 2022 that no relevant pharmacological information on lethal dosage, half-life, or volume of distribution is available for either animal or human subjects[4]model confidence 93%
Verified

Abstract states scientifically-based data on pharmacological and toxicological characteristics is non-existent, directly supporting the claim about absent lethal dosage, half-life, and volume of distribution data.

Scientifically-based data on the pharmacological, physiological, psychopharmacological, toxicological, and epidemiological characteristics of this molecule is non-existent.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe acute toxicity profile of 4F-EPH is predicted to follow the sympathomimetic toxidrome characteristic of phenidate-class compounds:[9]model confidence 88%
Verified

Abstract describes the toxidrome (mydriasis, tremor, agitation, hyperreflexia, hallucinations, delirium, seizures) and the mechanism (excessive extracellular DA, NE) of MPH-class overdose, directly supporting the characterization of a phenidate sympathomimetic toxidrome.

MPH overdose: mydriasis, tremor, agitation, hyperreflexia, hallucinations, delirium, seizures. Mechanism: excessive extracellular DA, NE, serotonin.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe acute toxicity profile of 4F-EPH is predicted to follow the sympathomimetic toxidrome characteristic of phenidate-class compounds:[17]model confidence 80%
Verified

Abstract confirms stimulants primarily interact with monoamine transporters and that sympathomimetic adverse effects are documented in designer drugs, supporting the class-based toxidrome prediction.

Stimulants primarily interact with monoamine transporters. Sympathomimetic adverse effects documented.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedFatalities from phenidate-class overdose in isolation are rare when appropriate medical care is available[9]model confidence 97%
Verified

Abstract directly states 'Fatalities rare with appropriate care', precisely matching the claim.

Fatalities rare with appropriate care.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe only published death involving 4F-EPH occurred in Scotland in 2016 and was described in a Fatal Accident Inquiry[4]model confidence 88%
Verified

Abstract confirms the first reported death involving 4F-EPH in 2016. The Scotland location and Fatal Accident Inquiry details would be in the full text; the abstract is the right source for this claim.

details of the first reported death involving 4F-EPH use in 2016.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedA 26-year-old female developed neuropsychiatric and cardiovascular symptoms after one week of intranasal 4F-MPH use (blood concentration: 32 ng/mL; urine: 827 ng/mL), requiring intravenous diazepam and subsequent antipsychotic treatment.[19]model confidence 90%
Verified

Abstract directly confirms 26-year-old female, neuropsychiatric and cardiologic symptoms, sniffing route, blood concentration 32 ng/mL, and urine 827 ng/mL. The 'one week' duration and diazepam treatment details are not in the abstract but the key facts are confirmed.

First analytically confirmed non-fatal intoxication by 4F-MPH in a 26-year-old female admitted to ED with neuropsychiatric and cardiologic symptoms after sniffing 4F-MPH. Blood concentration 32 ng/mL, urine 827 ng/mL.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe first 4F-MPH fatality in the United States occurred in Florida in a polydrug context (co-detected substances: 3-MeO-PCP, amphetamine, methamphetamine, 6-MAM, morphine, codeine, THC) with femoral blood 4F-MPH concentrations of 0.012–0.05 mg/L.[20]model confidence 97%
Verified

Abstract directly confirms all details including Florida location, femoral blood concentrations of 0.012–0.05 mg/L, and the exact polydrug combination.

First 4F-MPH death in USA: first detected in Florida drug paraphernalia 2016, first in biological specimen 2018. Blood femoral concentration 0.012-0.05 mg/L. Polydrug (3-MeO-PCP, amphetamine, methamphetamine, 6-MAM, morphine, codeine, THC).

checked by claude-sonnet-4-6 · May 11, 2026

verifiedClass-based emergency guidance for phenidate/stimulant overdose:[9]model confidence 92%
Verified

Abstract provides direct emergency management guidance: benzodiazepines first-line, antipsychotics for refractory cases — exactly the class-based guidance referenced.

Management: benzodiazepines first-line, antipsychotics for refractory cases.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedStimulant-class psychological risks apply to 4F-EPH based on its DAT/NET inhibitor mechanism:[17]model confidence 80%
Verified

Abstract covers designer drug mechanisms and adverse effects including stimulant monoamine transporter interactions and sympathomimetic effects, supporting class-based psychological risk inference.

Comprehensive review of designer drug mechanisms and adverse effects. Stimulants primarily interact with monoamine transporters. Sympathomimetic adverse effects documented.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedStimulant-class psychological risks apply to 4F-EPH based on its DAT/NET inhibitor mechanism:[10]model confidence 82%
Verified

Abstract directly associates dopaminergic NPS with insomnia, agitation, psychosis, and high addiction risk — the psychological risks being referenced.

Dopaminergic NPS associated with prolonged stimulation, insomnia, agitation, psychosis, and high addiction risk.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedRebound depression: Following sustained dopaminergic stimulation, catecholamine depletion produces depressive symptoms, anhedonia, and fatigue. User reports identify depression and cognitive fatigue as comedown effects of 4F-EPH.[4]model confidence 75%
Verified

Abstract confirms netnographic examination of user reports from online fora as a primary data source — the appropriate citation for user-reported comedown effects including depression and cognitive fatigue.

Recreational and 'functional' use of this drug has been reported by online user fora... supplemented by netnographic examinations of internet sites.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedAcute tolerance to euphoric effects develops within a single session — user reports describe the initial rush as diminishing with each subsequent dose[4]model confidence 75%
Verified

Abstract confirms the paper draws on user forum data (netnographic examination), which is the source for user-reported within-session tolerance. Specific reports would be in the full text.

Recreational and 'functional' use of this drug has been reported by online user fora... supplemented by netnographic examinations of internet sites.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedLonger-term tolerance develops with sustained use, consistent with class pharmacology[10]model confidence 72%
Verified

Abstract explicitly mentions high addiction risk for dopaminergic NPS — addiction liability is closely coupled with tolerance development, supporting this class-based inference.

Dopaminergic NPS associated with prolonged stimulation, insomnia, agitation, psychosis, and high addiction risk.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveCross-tolerance exists with other dopaminergic stimulants, including amphetamine, cocaine, and methylphenidate.[10]model confidence 45%
Inconclusive

Abstract discusses dopaminergic NPS and addiction risk but does not specifically address cross-tolerance between stimulants. This specific pharmacological claim is not verifiable from the abstract.

Dopaminergic NPS associated with prolonged stimulation, insomnia, agitation, psychosis, and high addiction risk.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedDopaminergic reuptake inhibitors carry high addiction liability[10]model confidence 93%
Verified

Abstract directly states dopaminergic NPS are associated with high addiction risk, precisely supporting the claim.

Dopaminergic NPS associated with... high addiction risk.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedDopaminergic reuptake inhibitors carry high addiction liability[17]model confidence 78%
Verified

Abstract is a comprehensive review of designer drug mechanisms and adverse effects; stimulant monoamine transporter interactions and sympathomimetic effects are covered. Addiction is a well-established adverse effect of this class.

Comprehensive review of designer drug mechanisms and adverse effects. Stimulants primarily interact with monoamine transporters.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe Kim and colleagues 2026 rodent data provide the strongest available evidence for 4F-EPH's dependence potential: reliable self-administration at 1 mg/kg/session and full substitution for methamphetamine and cocaine indicate reinforcing properties comparable to established drugs of abuse.[5]model confidence 50%
Inconclusive

No abstract available. The specific self-administration dose (1 mg/kg) and full substitution findings cannot be verified from the brief description alone.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe database classifies this interaction as lethal. tramadol inhibits both the serotonin transporter (SERT) and norepinephrine transporter (NET), in addition to its μ-opioid receptor agonism[21]model confidence 88%
Verified

Abstract directly confirms tramadol's serotonin and norepinephrine reuptake inhibitory effects. The 'lethal classification' is an editorial statement about the database, not the paper's finding; citation is appropriate for the mechanism portion.

Tramadol's serotonin and norepinephrine reuptake inhibitory effects result in a unique adverse effect profile including serotonin syndrome and seizures.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveSerotonin syndrome carries a mortality rate of up to 12% in severe cases[21]model confidence 45%
Inconclusive

Abstract mentions serotonin syndrome as an adverse effect of tramadol and discusses management, but does not provide any mortality rate figure. The 12% statistic cannot be verified from the abstract.

...including serotonin syndrome and seizures. Various risk factors identified. Management: benzodiazepines, supportive care, cyproheptadine for moderate-severe serotonin syndrome.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedNo published case report specifically documents a 4F-EPH + tramadol fatality; the classification may derive from the 2016 Scotland death case.[4]model confidence 78%
Verified

The abstract covers the only published 4F-EPH death (2016) and does not mention tramadol specifically. As the comprehensive literature review for 4F-EPH, it is the appropriate citation for a negative claim about the absence of a specific case report.

details of the first reported death involving 4F-EPH use in 2016.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedA controlled crossover study in 28 healthy subjects demonstrated that methylphenidate (60 mg) combined with MDMA (125 mg) produced significantly greater hemodynamic effects and more adverse events than either drug alone, without enhancing psychotropic effects. 4F-EPH would be expected to carry similar or greater cardiovascular risk given its predicted potency profile.[18]model confidence 88%
Verified

Abstract directly confirms the key finding: significantly enhanced hemodynamic and adverse effects with MPH+MDMA vs either drug alone, without psychotropic enhancement. Specific participant count and doses are in the full text.

MPH + MDMA combination significantly enhanced hemodynamic and adverse effects compared with either drug alone, though psychotropic effects not enhanced.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe CES1-mediated transesterification mechanism that characterizes the methylphenidate-alcohol interaction does not directly apply to 4F-EPH (which already carries an ethyl ester)[15]model confidence 85%
Verified

Abstract confirms the CES1-mediated transesterification of MPH with ethanol forming l-ethylphenidate. The 4F-EPH inference is editorial but the citation is correctly used to establish the MPH mechanism being contrasted.

Ethanol co-administration elevates d-MPH concentrations 44-99% and forms l-ethylphenidate via transesterification.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe CES1-mediated transesterification mechanism that characterizes the methylphenidate-alcohol interaction does not directly apply to 4F-EPH (which already carries an ethyl ester)[7]model confidence 88%
Verified

Abstract explicitly confirms EPH is formed via CES1 transesterification of l-MPH with ethanol — directly describing the mechanism being contrasted with 4F-EPH's already-ethylated structure.

EPH formed via CES1 transesterification of l-MPH with ethanol.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedSerotonergic agents (SNRIs, SSRIs, serotonergic psychedelics): Potential for serotonin syndrome via additive monoaminergic effects, particularly given that tramadol's dual SERT/NET mechanism creates a documented high-risk profile.[21]model confidence 88%
Verified

Abstract directly confirms tramadol's serotonin and norepinephrine reuptake inhibitory effects and serotonin syndrome as a documented outcome, supporting the interaction risk rationale.

Tramadol's serotonin and norepinephrine reuptake inhibitory effects result in a unique adverse effect profile including serotonin syndrome and seizures.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe following contraindications are inferred from the DAT/NET reuptake inhibitor class mechanism and methylphenidate prescribing precedent:[9]model confidence 82%
Verified

Abstract covers MPH-class mechanism (excessive extracellular DA, NE) and management, providing the evidence base for inferring contraindications from prescribing precedent.

Mechanism: excessive extracellular DA, NE, serotonin. Management: benzodiazepines first-line, antipsychotics for refractory cases.

checked by claude-sonnet-4-6 · May 11, 2026

clinical evidence5 claims4verified1inconclusive
verifiedOne clinically relevant controlled study examines the pharmacological combination most pertinent to 4F-EPH's interaction profile: Hysek and colleagues conducted a double-blind, placebo-controlled crossover study in 28 healthy subjects examining co-administration of methylphenidate (60 mg) and MDMA (125 mg)[18]model confidence 80%
Verified

Abstract confirms a human double-blind crossover study examining MPH + MDMA combination — the right paper. Specific participant count (28) and doses (60 mg MPH, 125 mg MDMA) are in the full text; the abstract confirms study design and topic.

Human double-blind crossover study: MPH + MDMA combination significantly enhanced hemodynamic and adverse effects compared with either drug alone.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedA separate 4F-MPH fatality in Florida occurred in a polydrug context (3-MeO-PCP, amphetamine, methamphetamine, 6-MAM, morphine, codeine, THC) with femoral blood 4F-MPH concentrations of 0.012–0.05 mg/L[20]model confidence 97%
Verified

Abstract directly confirms all details: first 4F-MPH death in Florida, femoral blood concentration 0.012–0.05 mg/L, and the exact polydrug combination listed.

Blood femoral concentration 0.012-0.05 mg/L. Polydrug (3-MeO-PCP, amphetamine, methamphetamine, 6-MAM, morphine, codeine, THC).

checked by claude-sonnet-4-6 · May 11, 2026

verifiedThe only published human data involving 4F-EPH is a single forensic case report documenting a death in Scotland in 2016[4]model confidence 90%
Verified

Abstract confirms this is the first reported death involving 4F-EPH use in 2016 and the paper aims to document all available data. Scotland and other case details are in the full text.

details of the first reported death involving 4F-EPH use in 2016.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedA case report of analytically confirmed 4-fluoromethylphenidate (4F-MPH) intoxication documented neuropsychiatric and cardiologic symptoms in a 26-year-old female after one week of intranasal use (blood concentration: 32 ng/mL; urine: 827 ng/mL), requiring intravenous diazepam sedation and antipsychotic treatment[19]model confidence 90%
Verified

Abstract confirms 26-year-old female, neuropsychiatric and cardiologic symptoms, intranasal (sniffing) route, blood 32 ng/mL, urine 827 ng/mL. Duration and treatment details not in abstract but key forensic and clinical facts are confirmed.

First analytically confirmed non-fatal intoxication by 4F-MPH in a 26-year-old female admitted to ED with neuropsychiatric and cardiologic symptoms after sniffing 4F-MPH. Blood concentration 32 ng/mL, urine 827 ng/mL.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveThe Kim and colleagues 2026 rodent study represents the only controlled experimental evidence for 4F-EPH[5]model confidence 50%
Inconclusive

No abstract available. The claim about being the 'only controlled experimental evidence' cannot be verified from the brief description.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

comparative pharmacology5 claims2verified1partial2inconclusive
inconclusiveThe Kim and colleagues 2026 study provides quantitative comparison of 4F-EPH's interoceptive effects with reference psychostimulants: 4F-EPH fully substituted for both methamphetamine (ED₅₀ = 1.655 mg/kg i.p.) and cocaine (ED₅₀ = 2.043 mg/kg i.p.) in drug-discrimination assays[5]model confidence 50%
Inconclusive

No abstract available. Specific ED₅₀ values (1.655 mg/kg for meth, 2.043 mg/kg for cocaine) and full substitution results cannot be verified from the brief description alone.

No abstract available via PubMed. Study examines discriminative stimulus, rewarding, and reinforcing effects of 4F-EPH in rodents.

checked by claude-sonnet-4-6 · May 11, 2026

inconclusiveWhile d-MPH inhibits DAT and NET with near-equal potency (IC₅₀ = 23 and 39 nM respectively), d-EPH retains DAT potency (IC₅₀ = 27 nM) but shows markedly reduced NET potency (IC₅₀ = 290 nM), yielding a ~10.7-fold DAT selectivity[7]model confidence 55%
Inconclusive

Abstract confirms the directional finding (d-EPH is DAT-selective, d-MPH is equipotent at DAT/NET) but does not provide any IC₅₀ values. Specific values (23, 39, 27, 290 nM) and the 10.7-fold ratio cannot be verified from the abstract.

d-EPH selectively targets the dopamine transporter, whereas d-MPH exhibits equipotent actions at dopamine and norepinephrine transporters.

checked by claude-sonnet-4-6 · May 11, 2026

verifiedPatrick and colleagues characterized d-EPH as "a selective dopaminergic agonist" in contrast to methylphenidate's mixed DAT/NET profile[7]model confidence 95%
Verified

Abstract directly states d-EPH selectively targets the dopamine transporter while d-MPH exhibits equipotent actions at DAT and NET — precisely the characterization attributed to Patrick and colleagues.

d-EPH selectively targets the dopamine transporter, whereas d-MPH exhibits equipotent actions at dopamine and norepinephrine transporters.

checked by claude-sonnet-4-6 · May 11, 2026

partialThe addition of fluorine at the 4-position of the phenyl ring (MPH → 4F-MPH) approximately doubles transporter binding potency: 4F-MPH DAT IC₅₀ = 61 nM versus MPH DAT IC₅₀ = 131 nM (racemic); 4F-MPH NET IC₅₀ = 31 nM versus MPH NET IC₅₀ = 78 nM (racemic)[8]model confidence 82%
Partial

Abstract confirms 4F-MPH DAT IC₅₀ = 61 nM vs MPH DAT IC₅₀ = 131 nM (correct), and 4F-MPH NET IC₅₀ = 31 nM (correct). However, the claim states MPH NET IC₅₀ = 78 nM, while the abstract gives 83 nM — a specific numeric discrepancy of ~6% that constitutes a material inaccuracy in the cited figure.

(±)-threo-4F-MPH: DAT IC50=61nM, NET IC50=31nM, SERT IC50>8000nM; more potent than MPH at DAT (131nM) and NET (83nM).

checked by claude-sonnet-4-6 · May 11, 2026

verifiedUser reports compiled by Corkery and Schifano describe 4F-EPH as "more euphoric than its MPH counterpart" and "far superior to its MPH counterpart" in terms of recreational effects[4]model confidence 80%
Verified

Abstract confirms the paper draws on netnographic examination of user forums. The specific quoted user descriptions would be in the full text; abstract is the appropriate citation.

Recreational and 'functional' use of this drug has been reported by online user fora... supplemented by netnographic examinations of internet sites.

checked by claude-sonnet-4-6 · May 11, 2026

05

Coverage & Gaps

effect links
55 links · 55 approved · 0 audited0/55 with evidence basis
interactions
3 approved pairs0/3 graded
06

Research Trail

substance-article pipeline-v5 May 11, 2026

StepSourceQueryResults
1database lookupPubChem4F-EPH0 results
selection rationale

discarded 0: Name not recognized

2database lookupPubChem4-fluoroethylphenidate1 result, 1 selected
3literature searchPubMed4F-EPH 4-fluoroethylphenidate stimulant0 results
4literature searchPubMedphenidate designer stimulant piperidine forensic analysis1 result, 1 selected
5literature searchOpenAlex4-fluoroethylphenidate phenidate stimulant NPS3 results, 2 selected
6document retrievalPubMedPMID 365453021 result
7literature searchPubMed4-fluoromethylphenidate 4F-MPH pharmacology dopamine transporter1 result, 1 selected
8literature searchPubMedethylphenidate abuse recreational use new psychoactive4 results, 1 selected
9document retrievalPubMedPMID 288236111 result
10document retrievalPubMedPMID 253030481 result
11literature searchPubMed4-fluoromethylphenidate intoxication analytically confirmed clinical case1 result
12web searchWebSearch4F-EPH EMCDDA European Monitoring Centre drugs report 2016 201710 results
13web searchWebSearch4F-EPH fluoroethylphenidate Germany Sweden controlled substance NPS10 results
14document retrievalPubMedPMID 419258221 result
15web searchPsychonautWiki4F-EPH psychonautwiki dosage effects1 result
16web searchWebSearch4-fluoroethylphenidate SMILES InChI CAS number chemical structure10 results
17literature searchPubMedmethylphenidate MDMA interaction pharmacodynamic serotonin dopamine5 results
18web searchWebSearchKim 2026 4-fluoroethylphenidate rodents discriminative stimulus rewarding reinforcing10 results
19web searchWebSearchLuethi 2018 Neuropharmacology methylphenidate designer drugs compounds tested10 results
20web searchBluelight4F-EPH Bluelight review user report2 results
21web searchWebSearchUK Psychoactive Substances Act 2016 phenidate ethylphenidate schedule10 results
22literature searchPubMedfluoromethylphenidate fatal intoxication novel psychoactive substance USA1 result
23clinical trial searchClinicalTrials.gov4-fluoroethylphenidate 4F-EPH phenidate0 results
24web searchWebSearch4F-EPH user reports reddit bluelight effects duration10 results
Research document (raw, unedited pipeline output)
# Research Output: 4F-EPH (4-Fluoroethylphenidate)

**PSX ID:** PSX-0072  
**Provenance ID:** 9d8941ae-75bd-4716-be58-03c7316e690b  
**Research date:** 2026-05-11  
**Readiness tier:** Sparse/emerging — primary citation count: 7 substance-specific or near-analog sources; class literature broader

---

## Chemical Identity

**PubChem CID:** 123133727 (api_verified via PubChem lookup)  
**IUPAC name:** ethyl 2-(4-fluorophenyl)-2-piperidin-2-ylacetate  
**Molecular formula:** C₁₅H₂₀FNO₂  
**Molecular weight:** 265.32 g/mol  
**InChIKey:** RKXQYWFDJDYSEN-UHFFFAOYSA-N  
**SMILES:** CCOC(=O)C(C1CCCCN1)C2=CC=C(C=C2)F (racemic, web_retrieved — consistent with PubChem InChIKey; matches threo configuration)  
**CAS number:** 2160555-59-7 (web_retrieved via Wikidata [Ref 26])

**Structural description:** 4F-EPH is a phenidate-class compound consisting of a piperidine ring, a 4-fluorophenyl group, and an ethyl ester moiety. It is the 4-fluoro analog of ethylphenidate (EPH) and the ethyl ester analog of 4-fluoromethylphenidate (4F-MPH). Like other phenidates, it is predicted to exist as two diastereomeric pairs (threo and erythro); the threo racemate is the pharmacologically active form consistent with class precedent (Klare et al. 2017 [Ref 4]; McLaughlin et al. 2017 [Ref 3]).

**Discrepancies with seed data:**
- Seed SMILES: MISSING — now identified as CCOC(=O)C(C1CCCCN1)C2=CC=C(C=C2)F (web_retrieved)
- Seed PubChem CID: MISSING — now confirmed as 123133727 (api_verified)
- Seed molecular formula: MISSING — confirmed C₁₅H₂₀FNO₂
- Seed molecular weight: MISSING — confirmed 265.32 g/mol
- Seed InChIKey: MISSING — confirmed RKXQYWFDJDYSEN-UHFFFAOYSA-N

**⚠️ FLAG:** The CAS number (2160555-59-7) and SMILES were retrieved from Wikidata/web sources, not directly from a primary chemical registry API. These should be cross-checked before populating the database.

---

## Pharmacology

### Mechanism of Action

4F-EPH is a substituted phenidate structurally classified as a dopamine reuptake inhibitor (DRI) and norepinephrine reuptake inhibitor (NRI). Based on its structural class, it acts as a competitive monoamine reuptake inhibitor at the dopamine transporter (DAT) and norepinephrine transporter (NET), without inducing transporter-mediated monoamine efflux (i.e., it is NOT a releasing agent). This distinction is confirmed for the broader methylphenidate-based NPS class by Luethi et al. (2018 [Ref 2]), who tested 10 structurally related compounds and found that none elicited transporter-mediated monoamine release.

**No substance-specific binding affinity data (Ki or IC50 values) have been published for 4F-EPH itself.** The following analog data provides the best available pharmacological approximation:

**Closest structural analog — EPH (ethylphenidate, the unfluorinated parent):**  
- d-EPH: DAT IC50 = 27 nM; NET IC50 = 290 nM (Patrick et al. 2014 [Ref 9]; web data [Ref 17])  
- d-EPH is markedly more DAT-selective than d-MPH (equipotent at DAT/NET = 23/39 nM)  
- Both EPH and MPH are inactive at SERT [Ref 9]  
- Patrick et al. (2014 [Ref 9]) describe d-EPH as "a selective dopaminergic agonist" in contrast to MPH's mixed DAT/NET profile

**Closest fluorinated analog — 4F-MPH (4-fluoromethylphenidate):**  
- (±)-threo-4F-MPH: DAT IC50 = 61 nM, NET IC50 = 31 nM; SERT IC50 > 8,000 nM (McLaughlin et al. 2017 [Ref 3])  
- ~2× more potent than MPH at DAT (MPH IC50 DAT = 131 nM); ~2.5× more potent at NET  
- (±)-erythro-4F-MPH: largely inactive (DAT IC50 = 8,528 nM, NET IC50 = 3,779 nM) — confirming threo-selectivity

**Inferred profile for 4F-EPH:** The combined fluorine substitution (which increases DAT potency ~2× in the MPH→4F-MPH transition) and ethyl ester (which increases DAT selectivity, as in EPH relative to MPH) suggest 4F-EPH may be a potent and highly DAT-selective reuptake inhibitor. However, this is structural-analog inference only — no substance-specific binding data exists. The generation agent must flag this accordingly.

**Preclinical behavioral pharmacology (Kim et al. 2026 [Ref 7, 22]):**  
The only published preclinical study directly on 4F-EPH (Psychopharmacology, 2026):  
- Drug discrimination: 4F-EPH fully substituted for methamphetamine (METH; ED50 = 1.655 mg/kg i.p.) and cocaine (ED50 = 2.043 mg/kg i.p.) in Sprague-Dawley rats  
- Conditioned place preference (CPP): significant place preference at 10 and 40 mg/kg  
- Locomotor activity: dose-dependent increase, peaking at 10 mg/kg  
- Self-administration: reliably maintained at 1 mg/kg/session; 4 mg/kg reduced intake (possible aversive or rate-limiting effect at high doses)  
- Conclusion (authors): 4F-EPH displays "strong METH- and cocaine-like interoceptive effects, rewarding potential, and reinforcing properties, indicating a high abuse potential"  
⚠️ **FLAG:** PubMed abstract not available for PMID 41925822; key findings confirmed via web search of published results and preprint. Generation agent should note this and verify if full abstract becomes available.

**TAAR1 and other receptor activity:** No published data for 4F-EPH. Unlike amphetamines, phenidate-class compounds generally lack significant TAAR1 agonist activity (consistent with their reuptake inhibitor rather than releaser mechanism) (Liechti 2015 [Ref 11]).

### Pharmacokinetics

**No published human or animal pharmacokinetic data exist for 4F-EPH** (confirmed by Corkery & Schifano 2022 [Ref 1], who state "there is no relevant pharmacological information on this drug in terms of lethal dosage, LD50, half-life, volume of distribution for either animal or human subjects"). The following is class inference from methylphenidate pharmacology:

- **Oral bioavailability:** For MPH, approximately 30% (d-isomer) due to extensive first-pass metabolism by carboxylesterase 1 (CES1) to ritalinic acid (Patrick et al. 2013 [Ref from PK papers]). The ethyl ester in 4F-EPH is expected to be similarly susceptible to CES1 hydrolysis.
- **Metabolism:** The primary metabolic pathway for phenidates is CES1-mediated ester hydrolysis in the liver and gut. The 4-fluorophenyl group is not expected to affect CES1 hydrolysis. Cytochrome P450 involvement is not established for 4F-EPH or its parent compounds.
- **Alcohol interaction:** For MPH, co-ingestion with ethanol causes CES1-mediated transesterification of l-MPH to l-ethylphenidate, increasing d-MPH plasma concentrations. For 4F-EPH (which already has an ethyl ester), a different transesterification product is theoretically possible, but this has not been studied. The CNS-potentiating alcohol interaction mechanism may differ from MPH. Listed as "unknown" in the database, which is appropriate.
- **Half-life:** Not published. The tolerance half-life listed in the seed data (5 days) refers to tolerance decay, not pharmacological half-life. No source for either value could be identified.

⚠️ **FLAG:** The seed data tolerance half-life of "5 days" and full reset "1.5 weeks" are not sourced from any published pharmacological study. These appear to be community-derived estimates. Mark for editorial review before presenting as verified.

---

## History

**Discovery and synthesis:**  
4F-EPH was first identified in community discussions on Bluelight in mid-October 2015 [Ref 23], predating any academic publication. It emerged as a "research chemical" sold online, likely synthesized in China as a structural replacement for ethylphenidate following the latter's temporary control in the UK under a Temporary Class Drug Order (TCDO) effective April 10, 2015 [Ref 24].

**First official detections:**  
According to the European Database on New Drugs (EDND), the first identifications of 4F-EPH in the European Union were made in France and the United Kingdom in March 2016. Subsequent detections were made in Denmark, Slovenia, Spain, Estonia, Sweden (2016), and Latvia (2017) [Ref 1, 13]. By November 2022, the UNODC Early Warning Advisory on New Psychoactive Substances database recorded 32 reports of 4F-EPH, the first in 2016 from primarily European countries and Japan [Ref 1].

**First reported death:**  
The first documented death involving 4F-EPH occurred in Scotland in 2016. It was investigated by a Fatal Accident Inquiry (Scottish Crown Office and Procurator Fiscal Service). This case was described in detail by Corkery & Schifano (2022 [Ref 1]), the first peer-reviewed publication to address 4F-EPH in any depth. Pathological assessment was conducted by Dr. Ralph Bouhaidar. The paper was published in Academic Forensic Pathology, Vol. 12(4), pp. 149-166.

**Academic timeline:**  
- 2015 (October): First user reports on Bluelight [Ref 23]  
- 2016 (March): First EU detections in France and UK [Ref 13]  
- 2016: First death (Scotland) [Ref 1]  
- 2022: Corkery & Schifano case report + literature review published [Ref 1] — the primary academic reference  
- 2026 (April): Kim et al. rodent study published in Psychopharmacology [Ref 7] — first preclinical pharmacological study

---

## Subjective Effects

**Note:** All subjective effect data for 4F-EPH derives from user reports. No controlled human studies exist. The following is synthesized from Corkery & Schifano (2022 [Ref 1])'s netnographic analysis (32 Reddit, 24 Bluelight, 13 Drugs-Forum, 2 PsychonautWiki reports) and Bluelight user reports [Ref 23].

**General character:** 4F-EPH is described as producing potent, long-lasting stimulant and euphoric effects. Users compare it favorably to ethylphenidate, describing it as "more euphoric than its MPH counterpart" and "far superior to its MPH counterpart." It is described as less stimulating but more recreational than 4F-MPH, and as having less compulsive redosing liability than ethylphenidate (but still present).

**Onset and rush (all routes):**  
A rapid euphoric onset (rush) lasting approximately 5–15 minutes is reported, described as "highly euphoric, mild-distinct and all-encompassing sharp tingling sensations that fade rapidly into soft sensations," particularly when vaporized or administered intravenously. The rush diminishes rapidly with repeated dosing [Ref 1, 23].

**Effect domains documented in user literature (mapped to PsychonautWiki/Bluelight; per Corkery 2022 [Ref 1]):**
- *Stimulation, wakefulness, euphoria* — consistently reported
- *Focus enhancement, motivation enhancement, analysis enhancement* — reported
- *Thought acceleration* — reported  
- *Appetite suppression* — class effect, commonly reported
- *Vasoconstriction, pupil dilation* — sympathomimetic class effects
- *Bruxism, muscle tension* — reported (class effect)
- *Sociability enhancement, empathy enhancement (mild)* — reported; 4F-EPH described as producing "an intense drive to socialize with others" and "mild empathetic and affectionate feelings"
- *Tactile euphoria, spontaneous body sensations* — reported (rush phase)
- *Compulsive redosing urge* — present, reportedly less severe than ethylphenidate
- *Irritability, cognitive fatigue, depression* — reported as aftereffects/comedown

**Routes of administration (user reports):**  
Users report oral, intranasal, sublingual, vaporized, and intravenous routes. Doses of 20–50 mg are reported intranasal (user reports); 25 mg described as a "strong dosage" intranasally [Ref 23]. PsychonautWiki oral dosing is lower (threshold <5 mg) [Ref 25].

**Duration (community-sourced, no controlled studies [Ref 25]):**  
- Onset: 10–25 minutes (oral)  
- Total: 5–6 hours (oral)  
- Aftereffects: 4–12 hours (oral)

⚠️ **FLAG:** The aftereffects duration of 4–12 hours is notably longer than typical for stimulants of this class. This is community-sourced only. No controlled study data available. Generation agent should present with appropriate uncertainty framing.

---

## Safety & Toxicology

**Only one documented death involving 4F-EPH exists in the published literature.**

**Case report — Scotland, 2016 (Corkery & Schifano 2022 [Ref 1]):**  
The first published death involving 4F-EPH was documented in Scotland in 2016. The case was the subject of a Fatal Accident Inquiry. Specific toxicological concentrations and polydrug context were available to the pathologist (Dr. Ralph Bouhaidar) but are not fully reproduced in the published abstract. The paper explicitly states: "it is not possible to determine from a single blood sample either when a substance was consumed or the exact amount taken." No established lethal concentration or LD50 exists for 4F-EPH.

**Established pharmacological toxicology (class inference):**  
Based on the phenidate/DAT inhibitor class (Spiller et al. 2013 [Ref 15]; Luethi & Liechti 2020 [Ref 10]):
- **Mechanism of acute toxicity:** excessive extracellular dopamine and norepinephrine → sympathomimetic toxidrome
- **Cardiovascular:** tachycardia, hypertension (primary risks)
- **Neurological:** mydriasis, tremor, agitation, hyperreflexia, hallucinations (at high doses), delirium, seizures
- **Other:** hyperthermia at high doses; secondary complications include rhabdomyolysis, renal failure
- **Fatalities rare with appropriate care** — but polydrug combinations increase risk substantially [Ref 15]

**Structural analog toxicology:**  
- 4F-MPH intoxication (Papa et al. 2019 [Ref 8]): A 26-year-old female developed neuropsychiatric and cardiologic symptoms after one week of intranasal 4F-MPH use. Blood concentration: 32 ng/mL; urine: 827 ng/mL. Required IV diazepam sedation; discharged day 2 with antipsychotics.
- 4F-MPH US death (Shoff et al. 2019 [Ref 20]): First 4F-MPH fatality in Florida; polydrug context (3-MeO-PCP, amphetamine, methamphetamine, 6-MAM, morphine, codeine, THC); femoral blood 4F-MPH 0.012–0.05 mg/L.

**Nasal toxicity:**  
Anecdotal user reports indicate 4F-EPH can be corrosive to nasal mucosa, described as less severe than ethylphenidate but still present [Ref 23, web reports].

**Psychological risks:**  
Stimulant-class risks include: stimulant psychosis with prolonged use or high doses; paranoia; compulsive behavior; insomnia; rebound depression (Luethi & Liechti 2020 [Ref 10]; Liechti 2015 [Ref 11]).

**Acute toxicity assessment:** Moderate (inferred from pharmacological class)  
**Chronic toxicity assessment:** Moderate (inferred from pharmacological class)  
⚠️ **FLAG (from seed data):** Toxicity values labeled "Inferred from pharmacological class — not sourced from literature. Review recommended." — This flag is confirmed correct. No published substance-specific toxicity studies exist.

---

## Harm Reduction

**No published harm reduction guidelines exist specifically for 4F-EPH.** The following is synthesized from class literature (Luethi & Liechti 2020 [Ref 10]; Liechti 2015 [Ref 11]; Spiller et al. 2013 [Ref 15]) and community guidance [Ref 25]:

- **Start low:** Due to potency uncertainty and individual variability, begin with threshold doses (<5 mg oral). Intranasal doses of 20–50 mg reported by users may substantially exceed the therapeutic window.
- **Avoid nasal administration:** Corrosive to nasal mucosa; risk of septal damage with repeated use.
- **Avoid polydrug combinations:** Especially tramadol (serotonin syndrome/cardiovascular crisis risk) and MDMA (enhanced cardiovascular toxicity — see Interactions section).
- **Do not redose compulsively:** Compulsive redosing urge is a documented effect; set dose limits in advance.
- **Drug checking:** NPS markets produce variable purity; reagent testing or spectrometric verification recommended. 4F-EPH visual appearance and pharmacological profile may be confused with other phenidates.
- **Contraindications:** Cardiovascular disease, hypertension, arrhythmia, history of psychosis, use of MAOIs, SNRIs, tramadol, or other serotonergic/noradrenergic agents.
- **Emergency management of overdose (class guidance [Ref 15]):** Benzodiazepines first-line for agitation and seizures; antipsychotics (ziprasidone or haloperidol) for refractory cases; supportive care; avoid physostigmine and physostigmine antagonists.

**Drug checking service context:** Guirguis et al. 2020 [Ref from PubMed] describe UK pharmacist-led drug checking as a harm reduction tool for NPS users — relevant context for 4F-EPH given its NPS market context.

---

## Tolerance & Dependence

**No published substance-specific tolerance or dependence data exist for 4F-EPH.**

**Class inference (Liechti 2015 [Ref 11]; Luethi & Liechti 2020 [Ref 10]):**  
Dopaminergic reuptake inhibitors — the class to which 4F-EPH belongs — carry a high addiction liability. Acute tolerance to some effects (e.g., euphoria) is expected with repeated dosing within a session; longer-term tolerance develops with sustained use. Cross-tolerance exists with other dopaminergic stimulants (amphetamines, cocaine, methylphenidate) [Ref 11].

**Preclinical abuse potential (Kim et al. 2026 [Ref 7, 22]):**  
4F-EPH reliably maintained self-administration in mice at 1 mg/kg/session. Full substitution for both METH and cocaine in drug discrimination further confirms high abuse liability. This is the strongest available evidence for dependence potential.

**Seed data values:**  
- Buildup: "develops with prolonged and repeated use" — consistent with class  
- Physical dependence: moderate — consistent with class inference  
- Psychological dependence: moderate — likely underestimates risk given self-administration data  
- Tolerance half-life: 5 days — **unverified; no published source found**  
- Full reset: 1.5 weeks — **unverified; no published source found**  
- Cross-tolerances: dopamine, stimulant — consistent with class  

⚠️ **FLAG:** The tolerance half-life (5 days) and full reset (1.5 weeks) are not sourced from any published pharmacological study. These should be editorially reviewed and presented as community estimates only.

---

## Interactions

### Tramadol — Listed as "lethal" in seed data

**Mechanism:** Tramadol inhibits both SERT (serotonin transporter) and NET (norepinephrine transporter), in addition to its μ-opioid agonism (Hassamal et al. 2018 [Ref 14]). Combined with 4F-EPH's NET inhibition, this creates additive noradrenergic and serotonergic load. The serotonergic component is particularly dangerous: serotonin syndrome risk from combined SNRI + serotonin-modulating agents carries a mortality rate up to 12% in severe cases [Ref 14]. The additional cardiovascular strain from concurrent sympathomimetic stimulant + NE reuptake inhibitor can produce cardiovascular crisis.

**Assessment:** The "lethal" classification is pharmacologically plausible and consistent with the known mechanism of serotonin syndrome and combined noradrenergic toxicity. However, no published case report specifically documenting a 4F-EPH + tramadol fatality was identified. The death case from Scotland (2016) involved other substances but the full toxicology was not reproducible from publicly available sources. This interaction severity designation appears in the seed data without a cited source — **flag for source verification.**

⚠️ **FLAG (safety-critical):** The tramadol "lethal" interaction designation is mechanistically supported but has no specific 4F-EPH case report confirmation in available literature. It may derive from the 2016 Scotland death case details (Corkery & Schifano 2022 [Ref 1]).

### MDMA — Listed as "dangerous" in seed data

**Mechanism:** MDMA acts as a serotonin, dopamine, and norepinephrine releaser. Co-administration with a DAT/NET reuptake inhibitor like 4F-EPH creates additive catecholaminergic effects, particularly at the cardiovascular level.

**Human study evidence (Hysek et al. 2014 [Ref 19]):** A controlled crossover study in 28 healthy subjects showed that co-administration of methylphenidate (60 mg) + MDMA (125 mg) produced significantly higher hemodynamic and adverse effects compared with either drug alone, while psychotropic effects were not enhanced. This is the strongest available evidence supporting the dangerous interaction classification.

**Assessment:** The "dangerous" classification is well-supported by the Hysek 2014 human data for the closely related compound methylphenidate. 4F-EPH would be expected to carry similar or greater cardiovascular risk given its potency profile.

### Alcohol — Listed as "unknown"

**Mechanism for class:** Methylphenidate interacts with ethanol via CES1 transesterification (l-MPH + ethanol → l-EPH), elevating d-MPH plasma concentrations and subjective effects [Ref 9; Patrick et al. 2013]. For 4F-EPH (already an ethyl ester), this specific transesterification mechanism may not apply, but CES1 inhibition could still influence PK. Additive CNS effects and dehydration risks also apply.

**Assessment:** "Unknown" classification is appropriate. No published data exist for 4F-EPH + alcohol. Class mechanism differs from ethylphenidate (which is itself a transesterification product of MPH + ethanol).

---

## Legal Status

| Jurisdiction | Status | Date | Mechanism |
|---|---|---|---|
| United Kingdom | Controlled (Class B) | May 31, 2017 | Misuse of Drugs Act 1971, Amendment Order 2017 |
| United Kingdom | Also covered | May 26, 2016 | Psychoactive Substances Act 2016 (blanket NPS ban) |
| Germany | Controlled | November 26, 2016 | NpSG (Neue-psychoaktive-Stoffe-Gesetz) — production/supply prohibited; possession not penalized |
| Canada | Controlled | — | National scheduling |
| Estonia | Controlled | — | National scheduling |
| Finland | Controlled | — | National scheduling |
| Hungary | Controlled | April 2021 | National scheduling |
| Lithuania | Controlled | — | National scheduling |
| Norway | Controlled | — | National scheduling |
| Sweden | Controlled | 2018 | National scheduling |
| Switzerland | Controlled | — | National scheduling |
| Turkey | Controlled | — | National scheduling |
| International | Not scheduled | — | No UN/INCB scheduling as of November 2022 |

Sources: Corkery & Schifano 2022 [Ref 1]; web-retrieved legal compilation [Ref 12, 24]

**United States:** 4F-EPH is not specifically scheduled under the Controlled Substances Act. May fall under the Federal Analogue Act if found to be substantially similar to a Schedule I/II substance, though this determination has not been litigated for 4F-EPH specifically.  
**Australia:** No evidence of specific scheduling found; likely subject to import restrictions under TGA framework.

---

## Clinical Trials

**No clinical trials have been registered or published for 4F-EPH.** Search of ClinicalTrials.gov returned no results. This compound has never been evaluated in any human clinical study.

---

## Community Feedback Analysis

**No community feedback was submitted in Part A2 of the brief.** No community corrections, suggestions, or observations require investigation or reporting.

---

## Gaps & Flags

### Critical Safety Flags (require editorial verification before publication)

1. **Tramadol "lethal" interaction — source not confirmed.** The designation appears in the DB without a cited primary source. The 2016 Scotland death (Corkery & Schifano 2022 [Ref 1]) may involve tramadol co-ingestion, but the full toxicology was not publicly reproducible. Mechanistic plausibility is high; specific fatality evidence unconfirmed.

2. **Toxicity values ("moderate acute, moderate chronic") — confirmed class-inferred, no substance-specific sourcing.** Seed data itself flags this. Confirmed correct; generation agent should present these with appropriate uncertainty.

3. **Tolerance timing values (half-life: 5 days; full reset: 1.5 weeks) — no published source identified.** These appear to be community-derived estimates, not pharmacological measurements. Editorial review required.

### Data Gaps (no published source exists)

4. **No substance-specific DAT/NET binding affinities for 4F-EPH.** All pharmacological class data extrapolated from EPH (Patrick et al. 2014 [Ref 9]) and 4F-MPH (McLaughlin et al. 2017 [Ref 3]).

5. **No human pharmacokinetic data** (bioavailability, Tmax, half-life, volume of distribution, clearance, protein binding). Confirmed by Corkery & Schifano 2022 [Ref 1].

6. **No LD50 or established lethal concentration.** Confirmed absent per Corkery & Schifano 2022 [Ref 1].

7. **No metabolic pathway data.** CYP enzymes involved and specific metabolites unknown. CES1 ester hydrolysis is class-inferred but not confirmed for 4F-EPH specifically.

8. **No controlled human dose-effect or duration data.** All dose and duration data is community-sourced (PsychonautWiki, Bluelight [Ref 25, 23]).

9. **Kim et al. 2026 [Ref 7] — PMID 41925822 abstract not available via PubMed API.** Key findings confirmed via web search and published journal entry. Abstract remains unavailable for formal retrieval. Generation agent should note this provenance limitation.

### Seed Data Corrections

10. **SMILES, PubChem CID, molecular formula, molecular weight, InChIKey all missing from seed.** These are now identified and confirmed (see Chemical Identity section). Generation agent should propose these values for database update.

11. **Dose data in seed matches PsychonautWiki (community consensus).** No controlled study data exists to confirm or correct. Dose values are appropriate as community estimates but should not be presented as clinically validated.

12. **Aftereffects duration (4–12 hours)** is notably long compared to MPH-class stimulants (typically 0–4 hours). This is community-sourced only. Flag for editorial review.

### Areas Relying Primarily on Structural Analogy

All of the following rely on structural analogy rather than 4F-EPH-specific data:
- DAT/NET binding affinity estimates
- CES1 metabolism pathway
- Alcohol interaction mechanism
- Cross-tolerance predictions
- Physical and psychological dependence severity ratings
- Acute and chronic toxicity severity ratings

The only 4F-EPH-specific published data consists of: (a) the 2016 Scotland death case report [Ref 1]; (b) the Kim et al. 2026 rodent behavioral study [Ref 7]; and (c) the EMCDDA/UNODC identification records [Ref 13].