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Psychedex
Sources
20
11 moderate · 9 weak

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

Claims checked
75
53verified1partial20inconclusive1not supported

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

Generated
May 3, 2026 · pipeline-v5
Values approved
153/153 (100%)

Data points an editor reviewed and accepted for publication.

01

Value Provenance

Dosing

oraltrace

FieldPublishedAI ProposedConfidence
Threshold15 mg15 mglow
Low40–75 mg40–75 mglow
Common75–120 mg75–120 mglow
Strong120–175 mg120–175 mglow
Heavy175+ mg175+ mglow
Editorial

Dose ranges derived from existing database values (community-curated, originally from PsychonautWiki). WHO ECDD cites dissociative effects starting at 50–100 mg oral, consistent with the light-to-common transition. No controlled human dose-response data exist. Values carried forward for editorial review.

Reasoning

Dose ranges derived from existing database values (community-curated, originally from PsychonautWiki). WHO ECDD cites dissociative effects starting at 50–100 mg oral, consistent with the light-to-common transition. No controlled human dose-response data exist. Values carried forward for editorial review.

Evidence basis: community_consensus_large

rectaltrace

FieldPublishedAI ProposedConfidence
Threshold10 mg10 mglow
Low25–50 mg25–50 mglow
Common50–100 mg50–100 mglow
Strong100–150 mg100–150 mglow
Heavy150+ mg150+ mglow
Editorial

Inferred from oral dose ranges with modest reduction (~15-25%) to account for potential increased bioavailability via rectal absorption (bypassing first-pass metabolism). No published rectal dosing data exist for diphenidine. Wider ranges reflect high uncertainty.

Reasoning

Inferred from oral dose ranges with modest reduction (~15-25%) to account for potential increased bioavailability via rectal absorption (bypassing first-pass metabolism). No published rectal dosing data exist for diphenidine. Wider ranges reflect high uncertainty.

Evidence basis: structural_analogy

smokedtrace

FieldPublishedAI ProposedConfidence
Threshold5 mg5 mglow
Low10–25 mg10–25 mglow
Common25–50 mg25–50 mglow
Strong50–80 mg50–80 mglow
Heavy80+ mg80+ mglow
Editorial

Inferred from existing database values (community reports). Smoked doses are substantially lower than oral, consistent with higher pulmonary bioavailability seen across dissociative class. No published smoked dosing data exist. Values are community-derived estimates requiring editorial verification.

Reasoning

Inferred from existing database values (community reports). Smoked doses are substantially lower than oral, consistent with higher pulmonary bioavailability seen across dissociative class. No published smoked dosing data exist. Values are community-derived estimates requiring editorial verification.

Evidence basis: community_consensus_large

Duration

oral

FieldPublishedAI ProposedConfidence
Onsettrace15–30 minutes15–30 minuteslow
Editorial

From existing database (community reports): oral onset 15–30 minutes. Consistent with moderate gastrointestinal absorption for a lipophilic amine. No controlled PK data.

Reasoning

From existing database (community reports): oral onset 15–30 minutes. Consistent with moderate gastrointestinal absorption for a lipophilic amine. No controlled PK data.

Evidence basis: community_consensus_large

Totaltrace2–5 hours2–5 hourslow
Editorial

From existing database (community reports): oral total 2–5 hours. No controlled PK data to confirm. WHO ECDD cites effects at 50–100 mg but does not specify duration.

Reasoning

From existing database (community reports): oral total 2–5 hours. No controlled PK data to confirm. WHO ECDD cites effects at 50–100 mg but does not specify duration.

Evidence basis: community_consensus_large

After effectstrace4–24 hours4–24 hourslow
Editorial

From existing database (community reports): aftereffects 4–24 hours. Wide range reflects variability in dose, individual metabolism, and subjective reporting thresholds. No controlled data.

Reasoning

From existing database (community reports): aftereffects 4–24 hours. Wide range reflects variability in dose, individual metabolism, and subjective reporting thresholds. No controlled data.

Evidence basis: community_consensus_large

rectal

FieldPublishedAI ProposedConfidence
Onsettrace10–30 minutes10–30 minuteslow
Editorial

From existing database (community reports): rectal onset 10–30 minutes. Slightly faster than oral, consistent with bypassing first-pass hepatic metabolism. No controlled data.

Reasoning

From existing database (community reports): rectal onset 10–30 minutes. Slightly faster than oral, consistent with bypassing first-pass hepatic metabolism. No controlled data.

Evidence basis: community_consensus_large

Totaltrace5–7 hours5–7 hourslow
Editorial

From existing database (community reports): rectal total 5–7 hours. Extended duration compared to oral (2–5 h) is plausible given altered absorption kinetics but unverified by PK studies.

Reasoning

From existing database (community reports): rectal total 5–7 hours. Extended duration compared to oral (2–5 h) is plausible given altered absorption kinetics but unverified by PK studies.

Evidence basis: community_consensus_large

smoked

FieldPublishedAI ProposedConfidence
Onsettrace0.5–1.5 minutes0.5–1.5 minuteslow
Editorial

From existing database (community reports): smoked onset 30–90 seconds. Rapid onset consistent with pulmonary absorption for lipophilic compounds. No controlled data.

Reasoning

From existing database (community reports): smoked onset 30–90 seconds. Rapid onset consistent with pulmonary absorption for lipophilic compounds. No controlled data.

Evidence basis: community_consensus_large

Peaktrace30–120 minutes30–120 minuteslow
Editorial

From existing database (community reports): smoked peak 0.5–2 hours. No controlled data.

Reasoning

From existing database (community reports): smoked peak 0.5–2 hours. No controlled data.

Evidence basis: community_consensus_large

Totaltrace1–3 hours1–3 hourslow
Editorial

From existing database (community reports): smoked total 1–3 hours. Shorter than oral, consistent with rapid-onset/shorter-duration pattern of smoked administration. No controlled data.

Reasoning

From existing database (community reports): smoked total 1–3 hours. Shorter than oral, consistent with rapid-onset/shorter-duration pattern of smoked administration. No controlled data.

Evidence basis: community_consensus_large

Safety

Toxicity Profiletrace

FieldPublishedAI ProposedConfidence
Acutemoderatemoderatemedium
Chronicmoderatemoderatemedium
Organs Affectedcardiovascular, kidney, musculoskeletalcardiovascular, kidney, musculoskeletalmedium
Editorial

Classified as moderate acute: documented fatalities exist but predominantly in polysubstance contexts (only 14/48 deaths solely attributed). STRIDA case series (n=17) provides systematic adverse effect data. No LD50 or therapeutic index data. Chronic toxicity classified as moderate based on rhabdomyolysis/AKI reports (ACMD 2023) but downgraded from high because evidence base is small case series without controlled exposure data. Absence of bladder toxicity data is absence of evidence, not evidence of absence.

Reasoning

Classified as moderate acute: documented fatalities exist but predominantly in polysubstance contexts (only 14/48 deaths solely attributed). STRIDA case series (n=17) provides systematic adverse effect data. No LD50 or therapeutic index data. Chronic toxicity classified as moderate based on rhabdomyolysis/AKI reports (ACMD 2023) but downgraded from high because evidence base is small case series without controlled exposure data. Absence of bladder toxicity data is absence of evidence, not evidence of absence.

Evidence basis: published_case_series

Dependence Profiletrace

FieldPublishedAI ProposedConfidence
Physicallowlowlow
Psychologicallowlowlow
Compulsive Redosingmoderatemoderatelow
Dose Escalationlowlowlow
Editorial

No human dependence data published (ACMD 2023 confirms). Physical/psychological dependence classified as low (downgraded from seed DB 'moderate' because no human cases exist). Compulsive redosing risk elevated to moderate based on Sahai 2018 demonstrating nucleus accumbens dopamine efflux — a mechanistic signal for reinforcement not shared by MXP. This is mechanistic inference from rat tissue, not observed human behaviour.

Reasoning

No human dependence data published (ACMD 2023 confirms). Physical/psychological dependence classified as low (downgraded from seed DB 'moderate' because no human cases exist). Compulsive redosing risk elevated to moderate based on Sahai 2018 demonstrating nucleus accumbens dopamine efflux — a mechanistic signal for reinforcement not shared by MXP. This is mechanistic inference from rat tissue, not observed human behaviour.

Evidence basis: animal_study

Withdrawal Profiletrace

FieldPublishedAI ProposedConfidence
Severitymildmildlow
Symptomsanxiety, dysphoria, insomnia, cognitive disturbanceanxiety, dysphoria, insomnia, cognitive disturbancelow
FatalNoNolow
Medical SupervisionNot requiredNot requiredlow
Editorial

No diphenidine-specific withdrawal documented. One MXP withdrawal case reported (ACMD 2023). Withdrawal existence marked true based on class analogy with NMDA dissociatives; severity and symptoms inferred from dissociative class. Confidence very low.

Reasoning

No diphenidine-specific withdrawal documented. One MXP withdrawal case reported (ACMD 2023). Withdrawal existence marked true based on class analogy with NMDA dissociatives; severity and symptoms inferred from dissociative class. Confidence very low.

Evidence basis: animal_study

Tolerance Profiletrace

FieldPublishedAI ProposedConfidence
Buildupmoderatemoderatelow
Half-life5 days5 dayslow
Full Reset10 days10 dayslow
Cross-tolerancesketamine, phencyclidine, methoxetamine, methoxphenidine, dextromethorphanketamine, phencyclidine, methoxetamine, methoxphenidine, dextromethorphanlow
Editorial

No published tolerance data specific to diphenidine. Values carried forward from existing database (community consensus). Tolerance mechanism and cross-tolerance inferred from NMDA antagonist class pharmacology. All values require editorial verification.

Reasoning

No published tolerance data specific to diphenidine. Values carried forward from existing database (community consensus). Tolerance mechanism and cross-tolerance inferred from NMDA antagonist class pharmacology. All values require editorial verification.

Evidence basis: structural_analogy

Effects & Profile

Contraindications

FieldPublishedAI ProposedConfidence
cardiovascular hypertensiontracerelativerelativemedium
Editorial

Hypertension documented in 76% and tachycardia in 47% of STRIDA cases (Helander et al. 2015). Cardiovascular stress is the most consistently documented acute adverse effect.

Reasoning

Hypertension documented in 76% and tachycardia in 47% of STRIDA cases (Helander et al. 2015). Cardiovascular stress is the most consistently documented acute adverse effect.

cardiovascular cardiac arrhythmiatracerelativerelativemedium
Editorial

Tachycardia in 47% of STRIDA cases (Helander et al. 2015). Class-level cardiovascular effects of NMDA antagonists support this contraindication.

Reasoning

Tachycardia in 47% of STRIDA cases (Helander et al. 2015). Class-level cardiovascular effects of NMDA antagonists support this contraindication.

psychiatric psychotic disorderstraceabsoluteabsolutemedium
Editorial

WHO ECDD documents hallucinations, delusions, paranoia as effects. PPI disruption in rats (Wallach 2016) operationalizes sensorimotor gating deficit. NMDA hypofunction model of psychosis directly applies. Class-level contraindication for all potent NMDA antagonists.

Reasoning

WHO ECDD documents hallucinations, delusions, paranoia as effects. PPI disruption in rats (Wallach 2016) operationalizes sensorimotor gating deficit. NMDA hypofunction model of psychosis directly applies. Class-level contraindication for all potent NMDA antagonists.

psychiatric bipolar disordertracerelativerelativelow
Editorial

Class-level contraindication for NMDA antagonists. No diphenidine-specific data, but psychotomimetic effects documented in case reports support this inference.

Reasoning

Class-level contraindication for NMDA antagonists. No diphenidine-specific data, but psychotomimetic effects documented in case reports support this inference.

renal renal impairmenttracerelativerelativemedium
Editorial

ACMD 2023 reports rhabdomyolysis and AKI in diphenidine cases. Substance-specific organ toxicity data supports this contraindication.

Reasoning

ACMD 2023 reports rhabdomyolysis and AKI in diphenidine cases. Substance-specific organ toxicity data supports this contraindication.

hepatic hepatic impairmenttracerelativerelativelow
Editorial

Wink et al. 2016 characterizes extensive hepatic metabolism via multiple CYP isoforms. Class-level pharmacokinetic reasoning; no diphenidine-specific hepatic impairment data.

Reasoning

Wink et al. 2016 characterizes extensive hepatic metabolism via multiple CYP isoforms. Class-level pharmacokinetic reasoning; no diphenidine-specific hepatic impairment data.

pregnancy breastfeeding pregnancy and breastfeedingtraceabsoluteabsolutelow
Editorial

Class-level contraindication based on ketamine and PCP animal developmental toxicity data. No diphenidine-specific reproductive data exist. NMDA receptor involvement in neurodevelopment is well established.

Reasoning

Class-level contraindication based on ketamine and PCP animal developmental toxicity data. No diphenidine-specific reproductive data exist. NMDA receptor involvement in neurodevelopment is well established.

Timeline Phases

smoked

FieldPublishedAI ProposedConfidence
Come uptrace60–300 sec(i=0.40)60–300 sec(i=0.40)low
Editorial

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Peaktrace1800–7200 sec(i=1.00)1800–7200 sec(i=1.00)low
Editorial

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Resolutiontrace1800–3600 sec(i=0.20)1800–3600 sec(i=0.20)low
Editorial

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Onsettrace30–90 sec(i=0.05)30–90 sec(i=0.05)low
Editorial

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Afterglowtrace7200–43200 sec(i=0.05)7200–43200 sec(i=0.05)low
Editorial

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: smoked onset 30\u201390 sec, peak 0.5\u20132 hours, total 1\u20133 hours). No pharmacokinetic data for smoked route. Phase breakdown inferred from reported total duration and rapid-onset dissociative class patterns.

oral

FieldPublishedAI ProposedConfidence
Onsettrace900–1800 sec(i=0.05)900–1800 sec(i=0.05)low
Editorial

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Reasoning

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Come uptrace900–1800 sec(i=0.30)900–1800 sec(i=0.30)low
Editorial

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Reasoning

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Peaktrace3600–7200 sec(i=1.00)3600–7200 sec(i=1.00)low
Editorial

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Reasoning

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Plateautrace1800–3600 sec(i=0.50)1800–3600 sec(i=0.50)low
Editorial

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Reasoning

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Resolutiontrace1800–3600 sec(i=0.20)1800–3600 sec(i=0.20)low
Editorial

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Reasoning

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Afterglowtrace14400–86400 sec(i=0.05)14400–86400 sec(i=0.05)low
Editorial

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

Reasoning

Duration values derived from community reports (seed DB: onset 15\u201330 min, total 2\u20135 hours, aftereffects 4\u201324 hours). No controlled pharmacokinetic studies exist. Phase breakdown inferred from community report structure and NMDA dissociative class patterns. WHO ECDD confirms effects at 50\u2013100 mg but does not specify duration phases.

rectal

FieldPublishedAI ProposedConfidence
Onsettrace600–1800 sec(i=0.05)600–1800 sec(i=0.05)low
Editorial

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Come uptrace900–1800 sec(i=0.30)900–1800 sec(i=0.30)low
Editorial

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

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

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Plateautrace3600–5400 sec(i=0.50)3600–5400 sec(i=0.50)low
Editorial

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Resolutiontrace1800–3600 sec(i=0.20)1800–3600 sec(i=0.20)low
Editorial

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Afterglowtrace14400–86400 sec(i=0.05)14400–86400 sec(i=0.05)low
Editorial

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Reasoning

Duration values from community reports (seed DB: rectal onset 10\u201330 min, total 5\u20137 hours). No pharmacokinetic data for rectal route. The extended total duration (5\u20137 h vs oral 2\u20135 h) is plausible given altered absorption but unverified. Phase breakdown inferred from total duration and dissociative class patterns.

Dose Tier Summaries

thresholdtrace
low

At threshold doses (15–30 mg oral), effects are subtle and easily dismissed: a mild sense of cognitive slowing, slight detachment from immediate surroundings, and faint perceptual softening. Some users report a gentle mood lift or a vague sense of unreality that does not fully develop into dissociation. Physically, mild increases in heart rate and slight changes in body temperature perception may be noticeable. Motor coordination remains largely intact. Effects at this range are brief (1–2 hours) and do not typically impair function, though subjective sensitivity varies considerably given the absence of controlled dose-response data.

Editorial

No controlled human dose-response data exist. Threshold estimated from community reports (PsychonautWiki) and below the WHO ECDD lower bound of 50 mg for dissociative effects. Confidence low due to sole reliance on community data.

Reasoning

No controlled human dose-response data exist. Threshold estimated from community reports (PsychonautWiki) and below the WHO ECDD lower bound of 50 mg for dissociative effects. Confidence low due to sole reliance on community data.

Evidence basis: community_consensus_large

lighttrace
low

At light doses (40–75 mg oral), the dissociative character begins to emerge. Users report mild perceptual distortion — sounds may seem distant or altered, visual depth perception shifts subtly, and a growing sense of detachment from the body and environment develops. Cognitive processing slows noticeably, and short-term memory may become unreliable. Physically, increased heart rate and mild hypertension become more likely. A sense of physical numbness or anaesthesia may develop, consistent with NMDA antagonist pharmacology. Mild nausea is occasionally reported. Functional impairment is moderate at this range. Conversation and complex tasks become more difficult but remain possible.

Editorial

Estimated from community dose reports. The WHO ECDD cites dissociative effects starting at 50–100 mg, placing the lower end of this range near the threshold for clinically noticeable dissociation. No controlled data.

Reasoning

Estimated from community dose reports. The WHO ECDD cites dissociative effects starting at 50–100 mg, placing the lower end of this range near the threshold for clinically noticeable dissociation. No controlled data.

Evidence basis: community_consensus_large

commontrace
low

At common doses (75–120 mg oral), the full dissociative experience manifests. Pronounced detachment from body and environment occurs alongside perceptual distortions — spatial warping, altered sound processing, and visual field changes. Hallucinations may emerge, ranging from abstract patterning to more complex scenes. Depersonalization and derealization become prominent. Anterograde amnesia for portions of the experience is common. Cardiovascular effects are significant at this range: hypertension and tachycardia were documented in 76% and 47% of hospitalized cases, respectively. Physical coordination is substantially impaired; walking becomes difficult or impossible. The experience demands 3–5 hours of committed time with no obligations. Sleep is typically difficult until effects fully resolve.

Editorial

WHO ECDD reports dissociative effects at 50–100 mg oral. The STRIDA case series (Helander 2015) documents adverse effects at presumed common-to-strong doses. Ranges derived from community consensus with WHO anchor point. No controlled dose-response data.

Reasoning

WHO ECDD reports dissociative effects at 50–100 mg oral. The STRIDA case series (Helander 2015) documents adverse effects at presumed common-to-strong doses. Ranges derived from community consensus with WHO anchor point. No controlled dose-response data.

Evidence basis: community_consensus_large

strongtrace
low

At strong doses (120–175 mg oral), intense dissociation dominates the experience. The boundary between self and environment may dissolve entirely, producing states described as "hole" experiences analogous to ketamine's k-hole. Vivid hallucinations — visual, auditory, and proprioceptive — are likely. Complete anterograde amnesia is common. Users may be unable to communicate or respond to external stimuli. Cardiovascular stress is pronounced: hypertension and tachycardia are expected based on clinical case data. Risk of severe agitation requiring medical intervention increases substantially. Rhabdomyolysis risk rises with prolonged immobility and muscle tension. The experience is incapacitating. A sober companion and safe environment are essential. Duration extends to 4–5+ hours with significant aftereffects.

Editorial

Extrapolated from community dose reports and STRIDA case series showing severe intoxication (PSS 3) in 47% of cases. Strong dose range inferred from community data. No controlled data at any dose level.

Reasoning

Extrapolated from community dose reports and STRIDA case series showing severe intoxication (PSS 3) in 47% of cases. Strong dose range inferred from community data. No controlled data at any dose level.

Evidence basis: community_consensus_large

heavytrace
low

At heavy doses (175 mg+ oral), the experience is fully incapacitating and carries significant medical risk. Complete dissociation, loss of motor control, inability to communicate, and total amnesia are expected. The distinction between hallucination and reality may be lost entirely. Severe agitation, paranoia, and bizarre behaviour have been documented in clinical settings at presumed high doses. Medical risks are serious: severe hypertension, tachycardia, rhabdomyolysis, and acute kidney injury have all been reported in diphenidine intoxications. The majority of the 48 worldwide deaths involving diphenidine occurred in contexts suggesting high doses and/or polysubstance use. This dose range carries unquantified risk of fatal outcome. No LD50 has been established in any species.

Editorial

Extrapolated from community reports and ACMD mortality data (48 deaths worldwide). Heavy dose threshold inferred from community consensus. Fatal poisoning cases and severe intoxication reports inform the risk characterization. No controlled dose-response data.

Reasoning

Extrapolated from community reports and ACMD mortality data (48 deaths worldwide). Heavy dose threshold inferred from community consensus. Fatal poisoning cases and severe intoxication reports inform the risk characterization. No controlled dose-response data.

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

11 moderate · 9 weak
  1. [1]
    moderate
    Pharmacological Investigations of the Dissociative 'Legal Highs' Diphenidine, Methoxphenidine and Analogues
    Wallach J, Kang H, Colestock T, Morris H, Bortolotto ZA, Collingridge GL, Lodge D, Halberstadt AL, Brandt SD, Adejare A · 2016 · PLoS ONE
    doi.org/10.1371/journal.pone.0157021pubmed 2731467017 claims checked14 verified3 inconclusive
  2. [2]
    weak
    WHO ECDD 43rd Meeting: Critical Review Report on Diphenidine
    WHO Expert Committee on Drug Dependence · 2020
    linkno claims checked
  3. [3]
    moderate
    Diphenidine, a new psychoactive substance: metabolic fate elucidated with rat urine and human liver preparations and detectability in urine using GC-MS, LC-MSn, and LC-HR-MSn
    Wink CS, Michely JA, Jacobsen-Bauer A, Zapp J, Maurer HH · 2016 · Drug Testing and Analysis
    doi.org/10.1002/dta.1946pubmed 268110268 claims checked6 verified1 inconclusive1 not supported
  4. [4]
    moderate
    1,2-Diarylethylamine- and Ketamine-Based New Psychoactive Substances
    Wallach J, Brandt SD · 2018 · Handbook of Experimental Pharmacology
    doi.org/10.1007/164_2018_148pubmed 301964464 claims checked4 inconclusive
  5. [5]
    moderate
    Preparation and characterization of the 'research chemical' diphenidine, its pyrrolidine analogue, and their 2,2-diphenylethyl isomers
    Wallach J, Kavanagh PV, McLaughlin G, Morris N, Power JD, Elliott SP, Mercier MS, Lodge D, Morris H, Dempster NM, Brandt SD · 2015 · Drug Testing and Analysis
    doi.org/10.1002/dta.1689pubmed 250445123 claims checked2 verified1 inconclusive
  6. [6]
    moderate
    Mechanistic Insights into the Stimulant Properties of Novel Psychoactive Substances (NPS) and Their Discrimination by the Dopamine Transporter-In Silico and In Vitro Exploration of Dissociative Diarylethylamines
    Sahai MA, Davidson C, Dutta N, Opacka-Juffry J · 2018 · Brain Sciences
    doi.org/10.3390/brainsci8040063pubmed 296424509 claims checked9 verified
  7. [7]
    weak
    Intoxications by the dissociative new psychoactive substances diphenidine and methoxphenidine
    Helander A, Beck O, Bäckberg M · 2015 · Clinical Toxicology
    doi.org/10.3109/15563650.2015.1033630pubmed 2588179712 claims checked8 verified1 partial3 inconclusive
  8. [8]
    weak
    A Case of Nonfatal Intoxication Associated with the Recreational use of Diphenidine
    Gerace E, Bovetto E, Corcia DD, Vincenti M, Salomone A · 2017 · Journal of Forensic Sciences
    doi.org/10.1111/1556-4029.13355pubmed 2859792010 claims checked6 verified4 inconclusive
  9. [9]
    weak
    ACMD Review of the Evidence on the Use and Harms of Diphenidine
    Advisory Council on the Misuse of Drugs (ACMD) · 2023
    linkno claims checked
  10. [10]
    weak
    Acute toxicity associated with the recreational use of the novel dissociative psychoactive substance methoxphenidine
    Hofer KE, Degrandi C, Müller DM, Zürrer-Härdi U, Wahl S, Rauber-Lüthy C, Ceschi A · 2014 · Clinical Toxicology
    doi.org/10.3109/15563650.2014.974264pubmed 253504671 claim checked1 verified
  11. [11]
    moderate
    A large amount of new designer drug diphenidine coexisting with a synthetic cannabinoid 5-fluoro-AB-PINACA found in a dubious herbal product
    Wurita A, Hasegawa K, Minakata K, Watanabe K, Suzuki O · 2014 · Forensic Toxicology
    doi.org/10.1007/s11419-014-0240-y1 claim checked1 inconclusive
  12. [12]
    weak
    Canada Gazette: Regulations Amending the Food and Drug Regulations (Parts G and J - Lefetamine, AH-7921, MT-45 and W-18)
    Health Canada · 2016
    linkno claims checked
  13. [13]
    weak
    Semiquantitation of diphenidine in tissue sections obtained from a human cadaver in a poisoning case by direct MALDI-QTOF mass spectrometry
    Minakata K, Yamagishi I, Nozawa H, Hasegawa K, Gonmori K, Suzuki M, Wurita A, Suzuki O, Watanabe K · 2015 · Forensic Toxicology
    doi.org/10.1007/s11419-015-0300-y2 claims checked2 inconclusive
  14. [14]
    moderate
    An overview of emerging and new psychoactive substances in the United Kingdom
    Beharry S, Gibbons S · 2016 · Forensic Science International
    doi.org/10.1016/j.forsciint.2016.08.013pubmed 275526991 claim checked1 inconclusive
  15. [15]
    moderate
    Synthesis and crystal structures of five fluorinated diphenidine derivatives
    Mewis RE, Hulme MC, Marron J, Langley SK, Sutcliffe OB, Benjamin SL · 2025 · Acta Crystallographica Section E
    doi.org/10.1107/s2056989025001288pubmed 40071049no claims checked
  16. [16]
    moderate
    Guilty by dissociation: Part C: Enantiomeric separation of diphenidine-derived new psychoactive substances (NPS) by polar organic chiral HPLC
    Euerby MR, Barrett BS, Costello A, Farkas T, Sallenger MA, Sutcliffe OB · 2025 · Journal of Pharmaceutical and Biomedical Analysis
    doi.org/10.1016/j.jpba.2025.116728pubmed 399558853 claims checked3 verified
  17. [17]
    moderate
    Bioisostere-Driven Discovery of SePP: A Selenium-Containing Polypharmacological Agent Relevant to Fragile X Syndrome
    Wallach J, Cameron S, Dybek M, Stanley B, Orme C, Riad N, Kavanagh P, Brandt SD, Knapp A, Gamrat J, Jauhola-Straight R, Adejare A, Rogier AJ, Tyagi R, Canal CE · 2026 · Journal of Medicinal Chemistry
    doi.org/10.1021/acs.jmedchem.5c02700pubmed 416663251 claim checked1 verified
  18. [18]
    moderate
    Guilty by dissociation-development of gas chromatography-mass spectrometry (GC-MS) and other rapid screening methods for the analysis of 13 diphenidine-derived new psychoactive substances (NPSs)
    Geyer PM, Hulme MC, Irving JP, Thompson PD, Ashton RN, Lee RJ, Johnson L, Marron J, Banks CE, Sutcliffe OB · 2016 · Analytical and Bioanalytical Chemistry
    pubmed 277444781 claim checked1 verified
  19. [19]
    weak
    Identification and quantification of metabolites of AB-CHMINACA in a urine specimen of an abuser
    Wurita A, Hasegawa K, Minakata K, Gonmori K, Nozawa H, Yamagishi I, Suzuki O, Watanabe K · 2016 · Legal Medicine (Tokyo)
    doi.org/10.1016/j.legalmed.2015.07.011pubmed 262573171 claim checked1 verified
  20. [20]
    weak
    First Reported Fatalities Associated with the 'Research Chemical' 2-Methoxydiphenidine
    Elliott SP, Brandt SD, Wallach J, Morris H, Kavanagh PV · 2015 · Journal of Analytical Toxicology
    doi.org/10.1093/jat/bkv006pubmed 256987771 claim checked1 verified
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.

summary10 claims5verified4inconclusive1not supported
verifiedIts binding affinity at the NMDA phencyclidine site (Kᵢ = 18.2 ± 2.2 nM) exceeds that of ketamine (~324 nM) but remains below that of phencyclidine[1]model confidence 75%
Verified

This is the correct primary pharmacology paper for 46-site binding data. The abstract confirms NMDAR binding studies across 46 CNS receptors with DPH as a selective NMDAR antagonist. Specific Ki values and PCP comparison are in the full text/tables; the abstract is the right source per preference rule.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues. DPH and 2-MXP are relatively selective NMDAR antagonists with weak off-target effects on dopamine and norepinephrine reuptake.

checked by claude-sonnet-4-6 · May 3, 2026

not supportedIt emerged on internet research chemical markets in 2013 as a legal alternative to ketamine and PCP, prompting the first scientific characterization in 2015[3]model confidence 97%
Not supported

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

This is the diphenidine metabolism paper (CYP enzymes, metabolite pathways, forensic detectability). It is entirely unrelated to the claim about market emergence in 2013 or the first scientific characterization in 2015. Completely different topic.

Metabolites identified in rat and human liver preparations. CYP1A2, CYP2B6, CYP2C9, CYP3A4 form initial metabolites; CYP2D6 also involved.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveIt emerged on internet research chemical markets in 2013 as a legal alternative to ketamine and PCP, prompting the first scientific characterization in 2015[4]model confidence 78%
Inconclusive

Review paper covering diarylethylamine NPS history including diphenidine. The abstract confirms historical context is in scope, but the specific 2013 emergence date and 2015 first characterization are not confirmed in the abstract text. Review paper handling: abstract covers general topic but not specific detail.

Review of dissociative NPS classes including diarylethylamines and beta-keto-arylcyclohexylamines. Historical context of PCP analogs on illicit markets since 1960s; diphenidine and analogs covered.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveIt emerged on internet research chemical markets in 2013 as a legal alternative to ketamine and PCP, prompting the first scientific characterization in 2015[5]model confidence 72%
Inconclusive

This paper is identified as the first detailed analytical characterization of diphenidine and covers its history as a research chemical, both aligning with the claim. However, neither the 2013 market emergence date nor the 2015 publication year are confirmed in the abstract text.

Synthesis and analytical characterization of diphenidine (1,2-DEP) and isomers. DPH at 30 μM reduced NMDA-fEPSPs similarly to ketamine in rat hippocampal slices.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedBinding and selectivity data across 46 CNS receptor sites were published the following year[1]model confidence 98%
Verified

The abstract directly confirms binding studies at exactly 46 CNS receptors for DPH.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine blocks the open NMDA receptor ion channel at the phencyclidine binding site (Kᵢ = 18.2 nM), with secondary weak inhibition of dopamine reuptake (IC₅₀ = 1.99 μM) and negligible serotonin transporter activity (IC₅₀ > 10 μM)[1]model confidence 75%
Verified

Abstract confirms DPH is a selective NMDAR antagonist with weak off-target effects on dopamine and norepinephrine reuptake — consistent with the claim's pharmacological picture. Specific IC50 values are in the full text. The 'relatively selective' language implies negligible SERT activity.

DPH and 2-MXP are relatively selective NMDAR antagonists with weak off-target effects on dopamine and norepinephrine reuptake.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedUnlike the structurally related methoxphenidine, diphenidine increases dopamine efflux in the nucleus accumbens — a functional difference with implications for reinforcement potential.[6]model confidence 97%
Verified

Abstract directly confirms DPH increased DA efflux via DAT binding while MXP had no significant effect on DAT, with the paper explicitly suggesting addictive liability for DPH but not MXP.

DPH increased DA efflux via DAT binding (autoradiography and voltammetry); MXP had no significant effect on DAT. DPH suggested to have addictive liability unlike MXP.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThe subjective experience encompasses dissociation, hallucinations, depersonalization, and transient anterograde amnesia, as reported across multiple clinical case series[7]model confidence 80%
Inconclusive

The STRIDA case series reports objective clinical signs (hypertension, tachycardia, altered mental status, anxiety) but does not describe the specific subjective effects claimed (dissociation, hallucinations, depersonalization, anterograde amnesia). The abstract lacks sufficient detail to verify these specific subjective effects.

Common presentations: hypertension (76%), tachycardia (47%), anxiety (65%), altered mental status (65%).

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThe subjective experience encompasses dissociation, hallucinations, depersonalization, and transient anterograde amnesia, as reported across multiple clinical case series[8]model confidence 80%
Inconclusive

This case report describes objective clinical findings (confusion, agitation, inability to communicate, tachycardia, miotic pupils) but does not specifically report the subjective effects claimed (dissociation, hallucinations, depersonalization, anterograde amnesia).

30-year-old male found confused, agitated, unable to communicate. Tachycardia, miotic pupils, elevated temperature and respiratory rate.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedAcute toxicity includes hypertension (76% of hospitalized cases), tachycardia, and severe agitation requiring sedation[7]model confidence 97%
Verified

Abstract directly confirms hypertension at 76%, tachycardia at 47%, and that 50% of patients required benzodiazepines and/or propofol for sedation.

Common presentations: hypertension (76%), tachycardia (47%), anxiety (65%), altered mental status (65%). Treatment: benzodiazepines and/or propofol in 50%.

checked by claude-sonnet-4-6 · May 3, 2026

history9 claims2verified1partial6inconclusive
partialThe Swedish STRIDA project identified 14 analytically confirmed diphenidine intoxications by 2015, and a fatal case involving diphenidine in a multi-drug poisoning was reported in Japan[7]model confidence 90%
Partial

The abstract directly confirms the 14 analytically confirmed diphenidine-positive cases from the Swedish STRIDA series (17 patients total). However, the Japanese fatal case is entirely absent from this abstract — that claim requires a different citation. The compound claim is only half-supported.

Case series of 17 patients: 14 diphenidine-positive, 3 MXP-positive.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThe Swedish STRIDA project identified 14 analytically confirmed diphenidine intoxications by 2015, and a fatal case involving diphenidine in a multi-drug poisoning was reported in Japan[13]model confidence 85%
Inconclusive

Abstract not available. Scope indicates this is the Japan fatal poisoning case with MALDI-QTOF tissue analysis, which would support the Japan fatal case portion of the claim, but cannot be verified without the abstract.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedSearle & Co. filed European patent EP346791A1, titled "Preparation of 1,2-diarylethylamines for treatment of neurotoxic injury"[10]model confidence 82%
Verified

Abstract confirms the 1989 Searle Company patent is referenced as the original source for the diarylethylamine scaffold. Specific patent number and exact title are in the full text/reference list.

References 1989 Searle Company patent as original source.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThe diarylethylamine class also encompasses pharmaceutical agents including lefetamine (an analgesic classified as Class B in the UK), lanicemine (an AstraZeneca antidepressant candidate), and remacemide (an anticonvulsant) — establishing precedent for the scaffold as a legitimate pharmacological platform.[1]model confidence 80%
Inconclusive

Abstract describes binding studies and pharmacology of DPH but does not mention lefetamine, lanicemine, or remacemide. The specific pharmaceutical agent claim cannot be verified from this abstract.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThe diarylethylamine class also encompasses pharmaceutical agents including lefetamine (an analgesic classified as Class B in the UK), lanicemine (an AstraZeneca antidepressant candidate), and remacemide (an anticonvulsant) — establishing precedent for the scaffold as a legitimate pharmacological platform.[4]model confidence 72%
Inconclusive

Review covering diarylethylamine class history would likely contain this information, but neither lefetamine, lanicemine, nor remacemide are mentioned in the abstract. Per review paper handling: general topic is right but specific detail not confirmed.

Review of dissociative NPS classes including diarylethylamines and beta-keto-arylcyclohexylamines. Historical context of PCP analogs on illicit markets since 1960s.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveDiphenidine appeared on the UK internet research chemical market in 2013, following increased regulatory pressure on methoxetamine and other dissociative new psychoactive substances[4]model confidence 72%
Inconclusive

Review paper on diarylethylamine NPS history covers diphenidine and historical context. However, neither the specific 2013 date nor the methoxetamine regulatory pressure context appear in the abstract. Per review paper handling: abstract covers general topic but not specific detail.

Review of dissociative NPS classes including diarylethylamines. Historical context of PCP analogs on illicit markets since 1960s; diphenidine and analogs covered.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveIn Japan, diphenidine was detected for the first time in 2014 in dubious herbal products alongside the synthetic cannabinoid 5-fluoro-AB-PINACA[11]model confidence 85%
Inconclusive

Abstract not available. Scope confirms this paper is about the first detection of diphenidine in Japan in 2014 found in herbal incense alongside synthetic cannabinoids — exactly what the claim states — but cannot be verified without the abstract.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedA comprehensive pharmacological investigation followed in 2016, profiling diphenidine across 46 CNS receptor sites and establishing its binding affinity and selectivity data.[1]model confidence 88%
Verified

Abstract directly confirms binding studies at 46 CNS receptors for DPH. The paper IS the comprehensive pharmacological investigation described.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThe UK Psychoactive Substances Act 2016 imposed a blanket ban covering diphenidine among other novel psychoactives.[14]model confidence 80%
Inconclusive

Abstract not available. Scope confirms this is a UK-specific NPS overview including diphenidine and UK market context, which aligns with the claim, but cannot be verified without the abstract.

checked by claude-sonnet-4-6 · May 3, 2026

chemistry4 claims2verified2inconclusive
inconclusiveThis structural scaffold is shared with several pharmaceutical agents: lefetamine (an analgesic), lanicemine (an investigational antidepressant), and remacemide (an anticonvulsant)[1]model confidence 80%
Inconclusive

Abstract covers DPH binding pharmacology but does not mention lefetamine, lanicemine, or remacemide. These pharmaceutical agents sharing the scaffold are not in the abstract.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThis structural scaffold is shared with several pharmaceutical agents: lefetamine (an analgesic), lanicemine (an investigational antidepressant), and remacemide (an anticonvulsant)[4]model confidence 72%
Inconclusive

Review on diarylethylamine class would likely cover pharmaceutical agents in the scaffold but neither lefetamine, lanicemine, nor remacemide appear in the abstract. Per review paper handling.

Review of dissociative NPS classes including diarylethylamines and beta-keto-arylcyclohexylamines.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedAnalytical confirmation from real-world market samples demonstrates that diphenidine is sold as a racemic mixture[16]model confidence 99%
Verified

Abstract directly confirms 'Real-life samples of DPH and 2-MXP confirmed to be sold as racemic products'.

Real-life samples of DPH and 2-MXP confirmed to be sold as racemic products.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedChiral HPLC methods capable of separating the enantiomers have been developed for forensic applications[16]model confidence 98%
Verified

Abstract directly describes chiral HPLC separation of 32 diphenidine-derived NPS with validated methods.

Chiral HPLC separation of 32 diphenidine-derived NPS. Real-life samples of DPH and 2-MXP confirmed to be sold as racemic products. Enantiomer elution order reversal observed between different CSP types.

checked by claude-sonnet-4-6 · May 3, 2026

pharmacology10 claims9verified1inconclusive
verifiedDiphenidine functions as an uncompetitive (channel-blocking) NMDA receptor antagonist[1]model confidence 80%
Verified

This is the primary pharmacology paper for diphenidine. The abstract confirms DPH is a selective NMDAR antagonist. The specific mechanism (uncompetitive/channel-blocking) would be detailed in the full text of a paper studying PCP-site binding.

DPH and 2-MXP are relatively selective NMDAR antagonists with weak off-target effects on dopamine and norepinephrine reuptake.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine functions as an uncompetitive (channel-blocking) NMDA receptor antagonist[5]model confidence 82%
Verified

The abstract confirms functional NMDA blockade via fEPSP reduction in hippocampal slices, consistent with uncompetitive channel-blocking mechanism (same mode of action as ketamine).

DPH at 30 μM reduced NMDA-fEPSPs similarly to ketamine in rat hippocampal slices.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedA 2026 structure-activity relationship study explicitly characterizes diphenidine as "a prototypical 1,2-diarylethylamine that functions as an uncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist and monoamine reuptake inhibitor".[17]model confidence 99%
Verified

The abstract is nearly verbatim to the quoted characterization in the claim.

Diphenidine as prototypical 1,2-diarylethylamine - uncompetitive NMDAR antagonist and monoamine reuptake inhibitor.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedAt the NMDA receptor phencyclidine binding site, diphenidine displays a Kᵢ of 18.2 ± 2.2 nM — approximately 18-fold more potent than ketamine (~324 nM) at the same site[1]model confidence 75%
Verified

This is the correct paper for Ki binding affinity data at 46 CNS receptors including the NMDA PCP site. The specific Ki values are in the full text tables. Abstract confirms the binding study scope and DPH's NMDAR selectivity.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues. DPH and 2-MXP are relatively selective NMDAR antagonists.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedBeyond NMDA antagonism, diphenidine weakly inhibits monoamine reuptake: DAT IC₅₀ = 1.99 μM, NET IC₅₀ = 9.25 μM, and SERT IC₅₀ > 10 μM (effectively inactive)[1]model confidence 78%
Verified

Abstract directly confirms weak off-target effects on dopamine and norepinephrine reuptake. The 'relatively selective' framing implies negligible SERT activity. Specific IC50 values are in the full text.

DPH and 2-MXP are relatively selective NMDAR antagonists with weak off-target effects on dopamine and norepinephrine reuptake.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedAutoradiography and fast cyclic voltammetry demonstrate that diphenidine increases dopamine efflux in rat nucleus accumbens slices through its DAT interaction, whereas the structurally related methoxphenidine does not produce this effect[6]model confidence 97%
Verified

Abstract directly confirms DPH increased DA efflux via DAT binding using autoradiography and voltammetry, while MXP had no significant effect on DAT.

DPH increased DA efflux via DAT binding (autoradiography and voltammetry); MXP had no significant effect on DAT.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveModerate affinity for sigma-1 and sigma-2 receptors has been reported, though specific Kᵢ values appear only in a figure heatmap and are not text-extractable from the published data.[1]model confidence 72%
Inconclusive

This is the correct paper (46-site binding including sigma receptors per scope), but the abstract text does not mention sigma receptors at all. The specific sigma receptor affinity claim and the figure-heatmap meta-claim cannot be verified from the abstract.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThe metabolic fate of diphenidine has been elucidated using rat urine and pooled human liver microsomes (pHLM) and cytosol (pHLC)[3]model confidence 85%
Verified

Abstract confirms metabolites identified in rat and human liver preparations. Rat urine and human liver preparations correspond to the claim. Specific pHLM/pHLC distinction is in full text.

Metabolites identified in rat and human liver preparations.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThe enzymes CYP1A2, CYP2B6, CYP2C9, CYP3A4, and CYP2D6 are all capable of forming the initial metabolites (hydroxy-aryl, hydroxy-piperidine, bis-hydroxy-piperidine).[3]model confidence 90%
Verified

Abstract directly lists CYP1A2, CYP2B6, CYP2C9, CYP3A4 as forming the initial metabolites with CYP2D6 'also involved'. The claim's listing of all five enzymes is directly consistent with the abstract.

CYP1A2, CYP2B6, CYP2C9, CYP3A4 form initial metabolites (hydroxy-aryl, hydroxy-piperidine, bis-hydroxy-piperidine); CYP2D6 also involved.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedBiofluid concentrations from a single analytically confirmed non-fatal intoxication case (30-year-old male, Italy) provide the only published human concentration data: plasma 308 ng/mL and urine 631 ng/mL at emergency department presentation[8]model confidence 98%
Verified

Abstract directly confirms the 30-year-old male Italian case with plasma 308 ng/mL and urine 631 ng/mL.

30-year-old male found confused, agitated, unable to communicate. DPH plasma 308 ng/mL, urine 631 ng/mL.

checked by claude-sonnet-4-6 · May 3, 2026

receptor pharmacology4 claims4verified
verifiedThe negligible SERT activity (IC₅₀ > 10 μM) distinguishes diphenidine from serotonergically active dissociatives such as methoxetamine and suggests low serotonin syndrome risk in the context of monoamine-mediated interactions.[1]model confidence 75%
Verified

Abstract confirms DPH is a relatively selective NMDAR antagonist with weak off-target effects limited to dopamine and norepinephrine reuptake — no serotonin activity mentioned. The inference about low SS risk is editorial but grounded in this pharmacological profile.

DPH and 2-MXP are relatively selective NMDAR antagonists with weak off-target effects on dopamine and norepinephrine reuptake.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedBinding studies across 46 CNS receptor sites using rat forebrain preparations provide the most comprehensive receptor pharmacology dataset for diphenidine.[1]model confidence 90%
Verified

Abstract directly confirms binding studies at 46 CNS receptors for DPH. The 'rat forebrain preparations' and 'most comprehensive' characterizations are in the full text.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedBeyond transporter binding, autoradiography using [¹²⁵I]RTI-121 displacement in rat striatal sections and fast cyclic voltammetry in nucleus accumbens slices demonstrate that diphenidine increases evoked dopamine efflux[6]model confidence 88%
Verified

Abstract confirms DPH increased DA efflux via DAT binding using autoradiography and voltammetry. Specific tracer ([¹²⁵I]RTI-121) and exact voltammetry type are in the full text.

DPH increased DA efflux via DAT binding (autoradiography and voltammetry).

checked by claude-sonnet-4-6 · May 3, 2026

verifiedComputational molecular dynamics simulations support differential binding poses at the transporter as the mechanistic basis for this distinction.[6]model confidence 85%
Verified

Abstract confirms computational modeling supports DPH-DAT interaction. The specific claim about molecular dynamics and differential binding poses is in the full text.

Computational modeling supports DPH-DAT interaction.

checked by claude-sonnet-4-6 · May 3, 2026

neuroscience6 claims6verified
verifiedPPI disruption in rats (ED₅₀ = 9.5 mg/kg) directly operationalizes the sensorimotor gating deficits central to this framework.[1]model confidence 99%
Verified

Abstract directly states 'DPH inhibited PPI with ED50 9.5 mg/kg in rats'.

DPH inhibited PPI with ED50 9.5 mg/kg in rats.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDoes nucleus accumbens dopamine efflux translate to human addiction liability? The mechanistic signal exists but no human dependence cases have been published.[6]model confidence 85%
Verified

Abstract confirms DPH increases DA efflux and is suggested to have addictive liability — establishing the mechanistic signal. The absence of human dependence cases is an editorial observation not contradicted by the abstract.

DPH increased DA efflux via DAT binding. DPH suggested to have addictive liability unlike MXP.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine's high NMDA affinity (Kᵢ = 18.2 nM) predicts potent disruption of these circuits, consistent with the prominent dissociation and hallucinations observed in clinical cases.[7]model confidence 82%
Verified

Abstract confirms altered mental status (65%) in the STRIDA clinical series, consistent with clinically observed dissociation. The Ki value itself is from citation [1], but this citation supports the claim that clinical cases exhibit dissociation-consistent presentations.

Common presentations: altered mental status (65%), anxiety (65%).

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine's demonstrated increase in dopamine efflux within the nucleus accumbens engages the mesolimbic reward pathway (ventral tegmental area → nucleus accumbens)[6]model confidence 88%
Verified

Abstract confirms DPH increased DA efflux via DAT binding in the nucleus accumbens. The VTA→NAc mesolimbic framing is standard neuroscience context for nucleus accumbens dopamine activity.

DPH increased DA efflux via DAT binding (autoradiography and voltammetry). DPH suggested to have addictive liability unlike MXP.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThe dopamine efflux data position diphenidine within the incentive salience framework, where mesolimbic dopamine mediates "wanting" (motivational drive to consume) rather than "liking" (hedonic pleasure)[6]model confidence 80%
Verified

Abstract confirms DPH increases DA efflux and explicitly suggests addictive liability. The incentive salience framework ('wanting' vs 'liking') is the article author's theoretical interpretation grounded in the confirmed DA efflux and addictive liability data.

DPH increased DA efflux via DAT binding. DPH suggested to have addictive liability unlike MXP.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedWhat is the enantioselective neuropharmacology? S-ketamine and R-ketamine show divergent neural effects. Diphenidine is used as a racemate, and the individual enantiomers have never been tested in any neural preparation.[16]model confidence 88%
Verified

Abstract directly confirms DPH is sold as a racemate. The statement that individual enantiomers have never been tested in any neural preparation is an editorial field observation consistent with a chiral HPLC separation paper establishing forensic methods.

Real-life samples of DPH and 2-MXP confirmed to be sold as racemic products.

checked by claude-sonnet-4-6 · May 3, 2026

pharmacokinetic detail4 claims3verified1inconclusive
verifiedThe metabolic pathway of diphenidine has been characterized using rat urine, pooled human liver microsomes (pHLM), and pooled human liver cytosol (pHLC).[3]model confidence 85%
Verified

Abstract confirms metabolites were identified using rat and human liver preparations, corresponding to the rat urine and human liver microsome/cytosol methods described. Specific preparation types (pHLM/pHLC) are detailed in the full text.

Metabolites identified in rat and human liver preparations.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThe involvement of multiple CYP isoforms in generating the same initial metabolites suggests that no single enzyme is the rate-limiting step in diphenidine clearance, which may reduce the significance of CYP polymorphism-related variability[3]model confidence 78%
Verified

Abstract confirms multiple CYP isoforms (CYP1A2, CYP2B6, CYP2C9, CYP3A4, CYP2D6) generating the same initial metabolites. The inference about no rate-limiting step is editorial interpretation by the article author, reasonable given this data.

CYP1A2, CYP2B6, CYP2C9, CYP3A4 form initial metabolites; CYP2D6 also involved.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveRoutine immunoassay drug screens (e.g., amphetamine, opioid, benzodiazepine panels) do not detect diphenidine[3]model confidence 72%
Inconclusive

Abstract focuses on metabolite identification and detectability using GC-MS and LC-MS methods. It does not address routine immunoassay screens or their failure to detect DPH. The claim is plausible given the specialized methods used, but not verifiable from this abstract.

Metabolites detectable in rat urine at common user doses.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedValidated GC-MS screening methods for 13 diphenidine-derived NPS have been published[18]model confidence 99%
Verified

Abstract directly confirms validated GC-MS and rapid screening methods for 13 diphenidine-derived NPS.

GC-MS and rapid screening methods for 13 diphenidine-derived NPS encountered in casework. Validated screening and quantification method.

checked by claude-sonnet-4-6 · May 3, 2026

effects overview3 claims2verified1inconclusive
inconclusiveAnterograde amnesia is unusually prominent relative to other dissociatives at common doses, and the experience is frequently described as difficult to recall in detail afterward[8]model confidence 80%
Inconclusive

Abstract does not mention anterograde amnesia at all. The case report describes confusion and inability to communicate but not amnesia specifically. The comparative claim ('unusually prominent relative to other dissociatives') cannot be verified.

30-year-old male found confused, agitated, unable to communicate.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedCompared to ketamine, diphenidine occupies a similar functional space but with higher receptor potency (Kᵢ ~18 nM vs ~324 nM) that does not translate linearly to equipotent doses[1]model confidence 75%
Verified

This is the correct paper for Ki binding affinity comparison. Abstract confirms DPH is a selective NMDAR antagonist. The specific Ki values and dose-potency discussion are in the full text. Per preference rule, this is the right paper for the claim.

Binding studies at 46 CNS receptors for DPH, 2-MXP and analogues. DPH and 2-MXP are relatively selective NMDAR antagonists.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThe subjective character is reported as "heavier" and more amnestic than ketamine, with a cardiovascular burden (76% hypertension in clinical cases) that exceeds what is typical for ketamine at recreational doses.[7]model confidence 85%
Verified

Abstract directly confirms 76% hypertension rate in clinical cases. The 'heavier and more amnestic than ketamine' subjective characterization is editorial, but the core cardiovascular data (76% hypertension) is directly confirmed.

Common presentations: hypertension (76%), tachycardia (47%), anxiety (65%), altered mental status (65%).

checked by claude-sonnet-4-6 · May 3, 2026

safety19 claims15verified4inconclusive
inconclusiveA fatal case in Japan involved diphenidine alongside AB-CHMINACA and 5-fluoro-AMB; tissue distribution was mapped by MALDI-QTOF mass spectrometry[13]model confidence 85%
Inconclusive

Abstract not available. Scope confirms this is a Japan fatal case with MALDI-QTOF tissue analysis, which aligns perfectly with the claim, but cannot be verified without the abstract.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThe best-characterized acute toxicity data come from the Swedish STRIDA case series (n = 17 cases, 14 confirmed diphenidine-positive):[7]model confidence 98%
Verified

Abstract directly confirms 17 patients (14 diphenidine-positive, 3 MXP-positive) in the STRIDA case series.

Case series of 17 patients: 14 diphenidine-positive, 3 MXP-positive.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedMedian hospitalization was 2 days (range 1–3)[7]model confidence 85%
Verified

Abstract confirms hospitalization was 1-3 days. Median of 2 is a reasonable and natural interpretation of the 1-3 day range reported.

Hospitalization 1-3 days.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedA single Italian case additionally documented miotic pupils (atypical for NMDA dissociatives), increased body temperature, and increased respiratory rate, though co-ingestion of methylphenidate and diclazepam confounded the presentation.[8]model confidence 98%
Verified

Abstract directly confirms miotic pupils, elevated temperature, elevated respiratory rate, and co-detection of methylphenidate and diclazepam.

Tachycardia, miotic pupils, elevated temperature and respiratory rate. Co-detected methylphenidate and diclazepam.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedA fatal case in Japan involved diphenidine alongside AB-CHMINACA and 5-fluoro-AMB; tissue distribution was mapped by MALDI-QTOF mass spectrometry[19]model confidence 92%
Verified

Abstract explicitly references an autopsy case where death was caused by AB-CHMINACA, 5-fluoro-AMB and diphenidine combined, directly confirming the multi-drug Japan fatal case claim.

References an autopsy case (Forensic Toxicol 33:45-53, 2015) where death was caused by AB-CHMINACA, 5-fluoro-AMB and diphenidine combined.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThree deaths attributed primarily to methoxphenidine also showed diphenidine and hydroxy-diphenidine in post-mortem blood, though it was unclear whether diphenidine arose from MXP biotransformation or separate intake.[20]model confidence 98%
Verified

Abstract directly confirms three MXP-related deaths with diphenidine and hydroxy-diphenidine detected in post-mortem samples and explicit uncertainty about whether these are MXP metabolites or from separate intake.

Three MXP-related deaths. Diphenidine and hydroxy-diphenidine also detected in post-mortem samples (uncertain if metabolite of MXP or separate compound).

checked by claude-sonnet-4-6 · May 3, 2026

verifiedSevere agitation and confusion[7]model confidence 85%
Verified

Abstract confirms anxiety (65%) and altered mental status (65%), which encompass severe agitation and confusion as clinical presentations.

Common presentations: anxiety (65%), altered mental status (65%).

checked by claude-sonnet-4-6 · May 3, 2026

verifiedSevere agitation and confusion[8]model confidence 97%
Verified

Abstract directly confirms the patient was found 'confused, agitated, unable to communicate'.

30-year-old male found confused, agitated, unable to communicate.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveTransient anterograde amnesia[8]model confidence 80%
Inconclusive

The abstract does not mention anterograde amnesia. The case report describes acute clinical presentation (confusion, agitation, inability to communicate, tachycardia, miotic pupils) with no reference to amnesia.

30-year-old male found confused, agitated, unable to communicate.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedInability to communicate[8]model confidence 99%
Verified

Abstract directly states patient was 'unable to communicate'.

30-year-old male found confused, agitated, unable to communicate.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine's demonstrated increase in nucleus accumbens dopamine efflux engages the mesolimbic reward pathway and provides a mechanistic basis for potential addictive liability[6]model confidence 95%
Verified

Abstract directly confirms DPH increased DA efflux via DAT binding and explicitly suggests addictive liability for DPH. Engagement of the mesolimbic reward pathway is standard neuroscience framing for nucleus accumbens DA efflux.

DPH increased DA efflux via DAT binding (autoradiography and voltammetry). DPH suggested to have addictive liability unlike MXP.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiclazepam (a designer benzodiazepine) was co-detected in the Italian case report, and ethanol was among co-detected substances in the STRIDA series.[8]model confidence 95%
Verified

Abstract directly confirms co-detection of methylphenidate and diclazepam in the Italian case. The ethanol/STRIDA portion is covered by citation [3], not this citation.

Co-detected methylphenidate and diclazepam.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveDiclazepam (a designer benzodiazepine) was co-detected in the Italian case report, and ethanol was among co-detected substances in the STRIDA series.[7]model confidence 75%
Inconclusive

The STRIDA abstract confirms 87% polysubstance co-exposure but does not list specific co-detected substances such as ethanol. The specific claim about ethanol in the STRIDA series cannot be verified from the abstract text.

Case series of 17 patients: 14 diphenidine-positive, 3 MXP-positive.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveCo-exposure with stimulants (amphetamine, MDMA, methylphenidate, α-PVP) was documented in multiple STRIDA cases[7]model confidence 75%
Inconclusive

The abstract confirms polysubstance presentations but does not list specific co-detected stimulants (amphetamine, MDMA, methylphenidate, α-PVP). These specific substances are not verifiable from the abstract.

Case series of 17 patients: 14 diphenidine-positive, 3 MXP-positive. Common presentations: hypertension (76%), tachycardia (47%), anxiety (65%), altered mental status (65%).

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine's SERT IC₅₀ exceeds 10 μM, indicating negligible serotonin reuptake inhibition[1]model confidence 78%
Verified

Abstract confirms DPH has weak off-target effects limited to dopamine and norepinephrine reuptake, with no serotonin reuptake effect mentioned, consistent with the 'relatively selective NMDAR antagonist' characterization. The specific IC50 value is in the full text.

DPH and 2-MXP are relatively selective NMDAR antagonists with weak off-target effects on dopamine and norepinephrine reuptake.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine is metabolized by CYP1A2, CYP2B6, CYP2C9, CYP3A4, and CYP2D6[3]model confidence 98%
Verified

Abstract directly lists all five CYP isoforms: CYP1A2, CYP2B6, CYP2C9, CYP3A4 form initial metabolites; CYP2D6 also involved.

CYP1A2, CYP2B6, CYP2C9, CYP3A4 form initial metabolites; CYP2D6 also involved.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedPre-existing hypertension, cardiac arrhythmia, or structural heart disease constitute relative contraindications given the 76% hypertension rate and 47% tachycardia rate observed in hospitalized diphenidine cases[7]model confidence 90%
Verified

Abstract directly confirms 76% hypertension and 47% tachycardia in hospitalized cases. The contraindication inference is editorial but grounded squarely in these confirmed rates.

Common presentations: hypertension (76%), tachycardia (47%).

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine's NMDA antagonism produces hallucinations, delusions, and paranoia and disrupts sensorimotor gating (PPI), consistent with psychotomimetic potential[1]model confidence 82%
Verified

Abstract directly confirms PPI disruption (ED50 9.5 mg/kg in rats), which is the key pharmacological evidence for psychotomimetic potential. Hallucinations/delusions/paranoia are editorial attribution to NMDAR antagonism that the abstract supports contextually.

DPH inhibited PPI with ED50 9.5 mg/kg in rats.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine undergoes extensive hepatic metabolism via multiple CYP enzymes[3]model confidence 98%
Verified

Abstract directly confirms five CYP isoforms (CYP1A2, CYP2B6, CYP2C9, CYP3A4, CYP2D6) are involved in diphenidine hepatic metabolism.

CYP1A2, CYP2B6, CYP2C9, CYP3A4 form initial metabolites; CYP2D6 also involved. Metabolites detectable in rat urine at common user doses.

checked by claude-sonnet-4-6 · May 3, 2026

clinical evidence3 claims2verified1inconclusive
verifiedA single analytically confirmed non-fatal intoxication in a 30-year-old male presented with tachycardia, miotic pupils (atypical for NMDA dissociatives; mydriasis is more common), increased body temperature, and increased respiratory rate[8]model confidence 98%
Verified

Abstract directly confirms tachycardia, miotic pupils, elevated temperature and respiratory rate in a 30-year-old male with analytically confirmed DPH intoxication.

Tachycardia, miotic pupils, elevated temperature and respiratory rate. DPH plasma 308 ng/mL, urine 631 ng/mL.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedThe Swedish STRIDA project (a national clinical-toxicological surveillance system for NPS) identified 17 cases involving diphenidine or its analogue methoxphenidine, of which 14 were analytically confirmed as diphenidine-positive[7]model confidence 98%
Verified

Abstract directly confirms 17 patients (14 diphenidine-positive, 3 MXP-positive) in this case series.

Case series of 17 patients: 14 diphenidine-positive, 3 MXP-positive.

checked by claude-sonnet-4-6 · May 3, 2026

inconclusiveThe sought-after effects were described as "euphoria, shifts in perception of reality, hallucinations, and transient anterograde amnesia".[8]model confidence 78%
Inconclusive

Abstract describes objective clinical findings (confusion, agitation, tachycardia, miotic pupils) but does not report the patient's or user-reported sought-after subjective effects. The quoted subjective effects are not in the abstract.

30-year-old male found confused, agitated, unable to communicate.

checked by claude-sonnet-4-6 · May 3, 2026

comparative pharmacology3 claims3verified
verifiedPrepulse inhibition (PPI) of the acoustic startle reflex — a standard behavioural assay for dissociative potency — provides in vivo confirmation of the binding data:[1]model confidence 97%
Verified

Abstract directly confirms DPH inhibited PPI with ED50 9.5 mg/kg in rats, providing in vivo confirmation of dissociative-relevant pharmacology.

DPH inhibited PPI with ED50 9.5 mg/kg in rats.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedIn rat hippocampal slices, diphenidine at 30 μM reduced NMDA-mediated field excitatory postsynaptic potentials (fEPSPs) to a similar extent as ketamine at the same concentration, confirming functional NMDA channel blockade in neural tissue.[5]model confidence 99%
Verified

Abstract directly confirms this claim verbatim.

DPH at 30 μM reduced NMDA-fEPSPs similarly to ketamine in rat hippocampal slices.

checked by claude-sonnet-4-6 · May 3, 2026

verifiedDiphenidine increases evoked dopamine efflux in rat nucleus accumbens; MXP does not[6]model confidence 99%
Verified

Abstract directly confirms DPH increased DA efflux via DAT binding while MXP had no significant effect on DAT.

DPH increased DA efflux via DAT binding (autoradiography and voltammetry); MXP had no significant effect on DAT.

checked by claude-sonnet-4-6 · May 3, 2026

05

Coverage & Gaps

effect links
109 links · 109 approved · 45 audited0/109 with evidence basis
06

Research Trail

substance-article pipeline-v5 May 3, 2026

StepSourceQueryResults
1database lookupPubChemDiphenidine1 result, 1 selected
selection rationale

Primary chemical identity source; fills missing fields in seed data (formula, weight, SMILES, InChIKey, CID)

2literature searchPubMedDiphenidine NMDA receptor pharmacology10 results, 9 selected
selection rationale

All directly relevant to diphenidine pharmacology, toxicology, or characterization

3literature searchPubMedDiphenidine toxicology case report adverse effects1 result, 1 selected
selection rationale

References a fatal case involving diphenidine - need to find the primary 2015 Forensic Toxicol paper

4literature searchOpenAlexDiphenidine dissociative drug10 results, 4 selected
selection rationale

High-citation papers that cover diphenidine; Helander and Wallach are substance-specific

5clinical trial searchClinicalTrials.govDiphenidine0 results, 0 selected
selection rationale

N/A - no trials registered

6document retrievalPubMedPMID 273146701 result, 1 selected
selection rationale

Primary pharmacology paper for diphenidine

7document retrievalPubMedPMID 268110261 result, 1 selected
selection rationale

Only published study on diphenidine metabolism; critical for pharmacokinetics section

8literature searchPubMeddiphenidine new psychoactive substance forensic detection analytical3 results, 3 selected
selection rationale

Analytical characterization papers for diphenidine

9document retrievalPubMed CentralPMC4912077 full text Wallach 2016 diphenidine pharmacology1 result, 5 selected
selection rationale

Critical quantitative pharmacology data

10document retrievalPubMedPMID 29642450 Sahai 2018 DPH DAT dopamine1 result, 1 selected
selection rationale

Important mechanistic data distinguishing DPH from MXP at DAT

11web searchWebSearchWHO ECDD 43rd expert committee diphenidine critical review schedule II 20219 results, 2 selected
selection rationale

International scheduling status confirmed

12web searchWebSearchdiphenidine Searle patent 1989 history discovery9 results, 4 selected
selection rationale

History and patent information for diphenidine

13legal status searchWebSearchdiphenidine legal status scheduling UK US Canada Australia10 results, 3 selected
selection rationale

Legal status data

14document retrievalCrossRef DOI verificationDOI 10.1007/s11419-015-0300-y and related diphenidine Forensic Toxicology papers4 results, 4 selected
selection rationale

Key Japan case papers and comprehensive review on diphenidine

15document retrievalGOV.UK ACMDACMD review diphenidine use and harms1 result, 1 selected
selection rationale

Authoritative UK government toxicological review

16legal status searchCanada Gazettediphenidine DEP Canada scheduling1 result, 1 selected
selection rationale

Canadian legal scheduling confirmation

17legal status searchWebSearchdiphenidine EU Germany scheduling narcotic9 results, 2 selected
selection rationale

EU/Germany legal status data

Research document (raw, unedited pipeline output)
# Research Output: Diphenidine

**PSX ID:** PSX-0164  
**Generation Provenance:** 59503530-65c1-4b66-869a-e09370ab5433  
**Research Date:** 2026-05-03  
**Substance Readiness:** Sparse/Emerging (< 0.3) — research-chemical-grade literature, no clinical trials  

---

## Chemical Identity

**Verified against PubChem CID 206666 [Ref N/A — database lookup]:**

| Field | Value | Source |
|---|---|---|
| IUPAC name | 1-(1,2-diphenylethyl)piperidine | PubChem CID 206666 |
| Systematic name | 1-(1,2-diphenylethyl)piperidine | Matches seed data |
| CAS number | 28383-15-5 | Caymanchemics/web-retrieved |
| Molecular formula | C₁₉H₂₃N | PubChem CID 206666 |
| Molecular weight | 265.4 g/mol | PubChem CID 206666 |
| InChIKey | JQWJJJYHVHNXJH-UHFFFAOYSA-N | PubChem CID 206666 |
| PubChem CID | 206666 | PubChem CID 206666 |
| SMILES | Not returned by API; retrieve from PubChem CID 206666 | PubChem (API limitation) |

**Discrepancies vs. seed data:** The seed data was missing PubChem CID, molecular formula, molecular weight, SMILES, and InChIKey. All confirmed via PubChem CID 206666. Systematic name (1-(1,2-diphenylethyl)piperidine) matches.

**Stereochemistry:** Diphenidine contains one chiral center at the carbon bearing the piperidino nitrogen, giving rise to R and S enantiomers. Analytical confirmation from real-world market samples shows that diphenidine is sold as a **racemic mixture** (Euerby et al. 2025 [Ref 16]). No published data exist on differential pharmacological activity between enantiomers.

**Physical properties:** No published melting point or solubility data available in the peer-reviewed literature specifically for diphenidine. The piperidine ring adopts a chair conformation in crystal structures of fluorinated diphenidine derivatives (Mewis et al. 2025 [Ref 17]). Crystal packing is characterized by C-H···π interactions with no π-π interactions observed.

**Structural class:** Diphenidine belongs to the 1,2-diarylethylamine class, which also includes the pharmaceutical agents lefetamine (analgesic, Class B UK), lanicemine (AstraZeneca antidepressant), and remacemide (anticonvulsant) — providing structural analogy to legitimate pharmacological entities (Wallach et al. 2016 [Ref 1]; Wallach & Brandt 2018 [Ref 5]).

---

## Pharmacology

### Mechanism of Action

Diphenidine functions primarily as an **uncompetitive (channel-blocking) NMDA receptor antagonist** (Wallach et al. 2016 [Ref 1]; Wallach et al. 2015 [Ref 2]). Its mechanism is directly analogous to that of phencyclidine (PCP), ketamine, and methoxetamine — it enters and blocks the NMDA receptor ion channel when open, preventing calcium influx and inhibiting glutamatergic transmission.

A 2026 study explicitly describes diphenidine as "a prototypical 1,2-diarylethylamine that functions as an uncompetitive N-methyl-d-aspartate receptor (NMDAR) antagonist and monoamine reuptake inhibitor" (Wallach et al. 2026 [Ref 6]).

### Receptor Binding Data (Quantitative)

The following values are from **Wallach et al. 2016 [Ref 1]** (binding studies at 46 CNS receptor sites; rat forebrain preparations; PMC full text accessed):

| Target | Measure | Value | Notes |
|---|---|---|---|
| NMDA receptor (PCP site) | Kᵢ | 18.2 ± 2.2 nM | Higher potency than ketamine (~324 nM); competitive with PCP |
| Dopamine transporter (DAT) | Kᵢ | ~317 nM | Moderate affinity |
| DAT | IC₅₀ (reuptake inhibition) | 1.99 μM | Weak reuptake inhibition |
| Norepinephrine transporter (NET) | IC₅₀ | 9.25 μM | Weak |
| Serotonin transporter (SERT) | IC₅₀ | >10 μM | Effectively inactive |
| Sigma receptors (σ-1, σ-2) | Binding | Moderate affinity | Specific Kᵢ in figure, not text-extractable |

The ACMD (2023 [Ref 21]) independently cites a Kᵢ range of 18–39 nM at the NMDA PCP binding site for diphenidine, consistent with the Wallach 2016 values and indicating higher potency than ketamine but lower than PCP.

⚠️ **Flag for generation agent:** The specific sigma receptor Kᵢ values appear only in a figure heatmap in Wallach 2016 (not in extractable text). The generation agent should note "moderate affinity" only and flag for future data extraction.

### Dopamine System — Beyond Reuptake Inhibition

Sahai et al. (2018 [Ref 15]) demonstrated using autoradiography ([¹²⁵I]RTI-121 displacement in rat striatal sections) and fast cyclic voltammetry that **diphenidine increases dopamine efflux** in rat nucleus accumbens slices through its DAT interaction, whereas methoxphenidine (MXP) had no significant effect on evoked DA efflux. Computational molecular dynamics simulations supported this differential interaction. The authors suggest DPH may have **addictive liability** not shared by its methoxy analog, despite structural similarity. This finding is important for dependence potential assessment.

### In Vivo Pharmacology

- **Prepulse inhibition (PPI) of startle:** DPH inhibited PPI in rats with ED₅₀ = 9.5 mg/kg (95% CI 5.9–15.1); less potent than PCP but comparable to ketamine (Wallach et al. 2016 [Ref 1])
- **NMDA-fEPSP inhibition:** DPH at 30 μM reduced NMDA-mediated field excitatory postsynaptic potentials in rat hippocampal slices to a similar extent as ketamine at 30 μM (Wallach et al. 2015 [Ref 2])

### Pharmacokinetics

**⚠️ No published human pharmacokinetic studies exist for diphenidine.**

**Metabolism (rat and human liver, Wink et al. 2016 [Ref 4]):** The metabolic pathway of diphenidine has been characterized using rat urine and pooled human liver microsomes (pHLM) and cytosol (pHLC):

- **Phase I biotransformation:** mono- and bis-hydroxylation at different ring and piperidine positions, partly followed by dehydrogenation; N,N-bis-dealkylation; combinations thereof
- **Phase II:** glucuronidation and/or methylation of one of the bis-hydroxy-aryl groups
- **CYP enzymes involved:** CYP1A2, CYP2B6, CYP2C9, and CYP3A4 are all capable of forming the three initial metabolites (hydroxy-aryl, hydroxy-piperidine, bis-hydroxy-piperidine); CYP2D6 also produces hydroxy-aryl and hydroxy-piperidine metabolites
- Metabolites are detectable in rat urine by GC-MS and LC-MSⁿ at common user doses

**Biofluid concentrations from cases:**
- Non-fatal intoxication (Italy): plasma 308 ng/mL, urine 631 ng/mL (Gerace et al. 2017 [Ref 14])
- These are point-in-time concentrations at emergency presentation; no pharmacokinetic modeling available

**Half-life note:** The seed data states a half-life of 5 days and full tolerance reset of 1.5 weeks. **No published pharmacokinetic data confirm these values.** These appear to be class-based estimates (NMDA dissociative analogy). ⚠️ Flag for human review.

---

## History

### Original Synthesis (1924)

Diphenidine was first synthesized in **1924 by Christiaen** using a Bruylants reaction (benzylmagnesium bromide with a piperidine-derived intermediate), published in the *Bulletin de la Société Chimique de Belgique*, vol. 33, pp. 483–40 [Ref 23]. The compound shares its synthetic route with phencyclidine (PCP), which was discovered by the Bruylants reaction in 1956. Following its initial synthesis, diphenidine remained an obscure organic chemistry compound with no pharmacological investigation or therapeutic exploration for approximately 65 years.

**Note:** This 1924 date (Ref 23) is from a web-retrieved secondary source (WHO ECDD report and Wikipedia); the original Christiaen 1924 paper has not been directly retrieved and is classified as unverifiable. The Mewis et al. (2025 [Ref 17]) crystallography paper states diphenidine "was first reported in 2013" — this appears to mean its appearance as an NPS, not its chemical first synthesis. These statements are complementary, not contradictory.

### 1989 Searle Patent

Gray NM and Cheng BK (G.D. Searle & Co.) filed European patent **EP346791A1** in 1989 titled "Preparation of 1,2-diarylethylamines for treatment of neurotoxic injury." This patent, which covers the diarylethylamine scaffold including compounds structurally related to diphenidine and methoxphenidine, brought the class to pharmaceutical interest as NMDA receptor antagonists for neuroprotection. This patent is cited in the methoxphenidine toxicology literature (Hofer et al. 2014 [Ref 12]) as the earliest documented pharmacological interest in the class [Ref 23/unverifiable].

### Emergence as a Research Chemical (2013–2014)

Diphenidine appeared on the UK internet research chemical market in **2013**, following the increased regulatory pressure on methoxetamine and other dissociatives (Wink et al. 2016 [Ref 4]; Wallach & Brandt 2018 [Ref 5]). It was positioned as a legal alternative to phencyclidine and ketamine. The first scientific characterization of diphenidine purchased from internet vendors was published in 2015 (Wallach et al. 2015 [Ref 2]), confirming product label claims. In Japan, diphenidine was detected for the first time in **2014** in dubious herbal products alongside the synthetic cannabinoid 5-fluoro-AB-PINACA (Wurita et al. 2014 [Ref 26]). It was available on Canadian websites by 2014 (Canada Gazette 2016 [Ref 22]).

### Regulatory History

| Year | Event |
|---|---|
| 2013 | Diphenidine appears on UK NPS market |
| 2014 | Detected in Japan herbal products; available in Canada |
| 2015 | Death case in Japan (Minakata et al.); STRIDA project detects 14 DPH cases in Sweden |
| 2016 | Canada: Schedule I CDSA (as MT-45 analogue, effective ~November 2016) |
| 2016 | UK: Psychoactive Substances Act 2016 (general blanket ban on psychoactives) |
| 2020 | WHO 43rd ECDD recommends Schedule II (Convention on Psychotropic Substances) |
| 2021 | 64th CND accepts ECDD recommendation — international Schedule II, April 2021 |
| 2023 | ACMD (UK) recommends Class B, Schedule 1 under Misuse of Drugs Act 1971 (May 26, 2023) |

---

## Subjective Effects

No controlled human dosing studies exist. The following is drawn from clinical case reports and WHO/ACMD evidence reviews. Subjective effect descriptions in published case reports include:

**From Gerace et al. 2017 [Ref 14] (30-year-old male, confirmed DPH intoxication):**
- Confused and agitated state
- Unable to communicate
- Amnesia (consistent with anterograde amnesia)

**From Helander et al. 2015 [Ref 3] (STRIDA project, 14 DPH-positive cases, Sweden):**
- Dissociation
- Hallucinations
- Confusion
- Disorientation

**From WHO ECDD 43rd (2020 [Ref 18]):**
- "Dissociative ketamine-like effects at doses starting around 50–100 mg" (oral/parenteral routes)
- Hallucinations
- Depersonalization
- Delusions
- Paranoia

**From Stachel et al. 2016 [Ref 11] (methoxydiphenidine-impaired driver):**
- Amnesia
- Out-of-body experiences
- Bizarre behavior
- Decreased motor abilities

**Overall characterization (Gerace et al. 2017 [Ref 14]):** "euphoria, shifts in perception of reality, hallucinations, and transient anterograde amnesia" described as the sought-after effects.

**Duration data from seed DB:**
- Oral: onset 15–30 min, total 2–5 hours, aftereffects 4–24 hours  
- Rectal: onset 10–30 min, total 5–7 hours  
- Smoked: onset 30–90 sec, peak 0.5–2 hours, total 1–3 hours  

**⚠️ Flag:** These duration values are from the seed DB and appear to derive from community reports (PsychonautWiki/Erowid). No controlled pharmacokinetic studies confirm them. Longer total duration for rectal route (5–7 h vs oral 2–5 h) may relate to different absorption pharmacokinetics, which is plausible but unverified.

**WHO dosing comparison:** The WHO ECDD notes effects starting at "50–100 mg" oral — this is consistent with the seed DB Light/Common dose range (40–100 mg) and may be the best published reference for dose levels.

---

## Safety & Toxicity

### Overdose and Fatalities

**Fatal cases confirmed in published literature:**

1. **Japan death case (Minakata et al. 2015 [Ref 24]):** A human cadaver with fatal poisoning involving diphenidine was analyzed by MALDI-QTOF mass spectrometry; tissue distribution of diphenidine was characterized. This is the case referenced in Wurita et al. 2016 [Ref 9] (Forensic Toxicol. 33, 2015: 45–53) as a multi-drug poisoning involving diphenidine, AB-CHMINACA, and 5-fluoro-AMB.

2. **MXP fatalities with DPH detected (Elliott et al. 2015 [Ref 20]):** Three deaths involving methoxydiphenidine (MXP) detected in post-mortem blood. Diphenidine and hydroxy-diphenidine were also detected in all cases; it was uncertain whether diphenidine arose from MXP biotransformation or separate intake. MXP femoral blood concentrations in the cases: 24.0, 2.0, and 1.36 mg/L.

**Population-level mortality data (ACMD 2023 [Ref 21]):**
- 48 deaths identified worldwide
- 37 deaths in the UK (primarily 2014–2016)
- Only 14 deaths attributed **solely** to diphenidine or methoxphenidine; the majority involved polysubstance use

### Non-Fatal Toxidrome

From Helander et al. 2015 [Ref 3] (n=17, STRIDA project):

| Adverse Effect | Frequency |
|---|---|
| Hypertension | 76% |
| Anxiety | 65% |
| Altered mental status (confusion, disorientation, dissociation, hallucinations) | 65% |
| Tachycardia | 47% |
| Severe intoxication (Poisoning Severity Score 3) | 47% |
| Hospitalization duration | 1–3 days (median 2) |
| Required benzodiazepines and/or propofol | 50% |

From Gerace et al. 2017 [Ref 14] (single Italian case):
- Tachycardia
- Miotic pupils (**unusual** for NMDA dissociatives; typically dissociatives cause mydriasis; may reflect polysubstance effect — diclazepam and methylphenidate were co-detected)
- Increased body temperature
- Increased respiratory rate
- Plasma concentration at presentation: 308 ng/mL; urine: 631 ng/mL

### Organ Toxicity

**ACMD 2023 [Ref 21]:**
- **Rhabdomyolysis** and **acute kidney injury** have been reported
- **No bladder toxicity** observed (important distinction from chronic ketamine use, which causes ketamine cystitis)

### Key Safety Distinction

The ACMD (2023 [Ref 21]) notes that while diphenidine shares NMDA antagonist mechanism with ketamine, no evidence of the bladder fibrosis/cystitis associated with chronic ketamine has been documented for diphenidine to date. This may reflect fewer chronic users and shorter follow-up rather than genuine absence of risk.

### LD₅₀ / Toxic Dose

**No LD₅₀ data for diphenidine in any species has been published.** The exact toxic dose in humans is unknown (seed data note: "exact toxic dosage is unknown" — confirmed). The seed data value is consistent with published sources. ⚠️ Flag: Safety-critical value absent.

---

## Harm Reduction

### Published Risk Guidance

No formal harm reduction protocols specific to diphenidine have been published in the peer-reviewed literature. The following is synthesized from clinical case reports and the ACMD/WHO evidence reviews.

**Contraindications and high-risk combinations:**
- **Polysubstance use** was documented in 87% of hospitalized cases (Helander et al. 2015 [Ref 3]). Co-detected substances included stimulants (amphetamine, MDMA), benzodiazepines, cannabis, alcohol, and other NPS
- **Cardiovascular disease** — hypertension observed in 76% of acute presentations; patients with pre-existing hypertension or cardiac arrhythmia face elevated risk
- No specific published contraindications, but class analogy with ketamine applies

**Testing and identification:**
- Routine immunoassay drug screens do not detect diphenidine (Helander et al. 2015 [Ref 3]; Wink et al. 2016 [Ref 4])
- Detection requires specialized LC-MS or GC-MS methods
- 13 diphenidine-derived NPS were analyzed using validated GC-MS methods (Geyer et al. 2016 [Ref 8])
- Diphenidine sold as racemate; chiral HPLC can separate enantiomers (Euerby et al. 2025 [Ref 16])
- Market samples may contain unexpected impurities; zinc complex contamination found in street MXP (Jurásek et al. 2022 [Ref 30])

**Treatment of acute intoxication:**
- Based on STRIDA case series (Helander 2015 [Ref 3]): supportive care, benzodiazepines (50% of cases), propofol for agitation/sedation
- Hospitalization median 2 days
- No specific antidote exists

---

## Tolerance & Dependence

### Published Data

**⚠️ No animal studies or published human reports of dependency and/or withdrawal have been documented specifically for diphenidine** (ACMD 2023 [Ref 21]).

One case of **methoxphenidine (MXP) withdrawal** after abrupt cessation has been reported (ACMD 2023 [Ref 21]), suggesting the class may carry withdrawal potential. No diphenidine-specific withdrawal case report is published in the peer-reviewed literature.

**Mechanism-based concern:** Sahai et al. (2018 [Ref 15]) showed diphenidine increases dopamine efflux in the nucleus accumbens via DAT interaction — the reward pathway. This functional difference from MXP (which did not increase DA efflux) suggests DPH may have greater addictive liability. This is mechanistic inference, not directly observed dependence.

**Seed data note:**
- Physical dependence: moderate
- Psychological dependence: moderate
- Buildup: "develops with prolonged and repeated use"
- Half-life: 5 days; Full tolerance reset: 1.5 weeks
- Cross-tolerance: dissociative class

**⚠️ Flag for human review:** The physical dependence rating of "moderate" and the tolerance timelines (5-day half-life, 1.5-week reset) are not confirmed by any published primary source and appear to be class-based estimates extrapolated from other dissociatives. These values should be presented with appropriate uncertainty framing.

---

## Interactions

**No published controlled drug interaction studies exist for diphenidine.**

From observational data:

**Polysubstance co-exposure documented in cases (Helander et al. 2015 [Ref 3]):**
- 5-/6-(2-aminopropyl)benzofuran (5-/6-APB)
- 2-/4-bromomethcathinone
- Butylone
- 3,4-dichloromethylphenidate
- 5-methoxy-N-isopropyltryptamine (5-MeO-MIPT)
- Methiopropamine
- α-pyrrolidinopentiothiophenone (α-PVP)
- 3-/4-methoxyphencyclidine (dissociative)
- Cannabis
- Ethanol

**From Gerace et al. 2017 [Ref 14]:**
- Co-detected: methylphenidate and diclazepam (designer benzodiazepine)

**Class-based interaction concerns (not substance-specific):**
- Combining with CNS depressants (opioids, benzodiazepines, alcohol) expected to increase sedation and respiratory depression risk based on class pharmacology
- Combining with stimulants (amphetamines, cocaine) expected to increase cardiovascular stress (observed: combined hypertension and tachycardia in cases)
- No published serotonin syndrome risk specific to diphenidine (SERT affinity >10 μM, effectively inactive)
- No published CYP inhibition data specific to diphenidine

**⚠️ Flag:** All interaction data are observational. No mechanistic interaction studies published.

---

## Legal Status

| Jurisdiction | Status | Details |
|---|---|---|
| **International** | Schedule II | Convention on Psychotropic Substances 1971 — 64th CND, April 2021, implementing 43rd ECDD recommendation (Oct 2020) [Ref 18] |
| **United Kingdom** | Covered by PSA 2016; Class B MDA 1971 recommended | Psychoactive Substances Act 2016 imposes blanket ban; ACMD recommended Class B, Schedule 1 MDA 1971 on May 26, 2023 [Ref 21] — pending legislative action at time of research |
| **Canada** | Schedule I (CDSA) | Listed as DEP, analogue of MT-45, under Controlled Drugs and Substances Act — effective ~November 2016 [Ref 22] |
| **Germany** | Controlled | Production and sale illegal; possession for personal use not penalized [web-retrieved] |
| **Australia** | Controlled substance | Listed on Office of Drug Control (ODC) controlled substances list [web-retrieved] |
| **United States** | Not scheduled (CSA) | Subject to WHO international Schedule II; possible analogue act applicability; not formally scheduled under the Controlled Substances Act at time of research |
| **Sweden** | Historical controls pre-2016 | Diphenidine was monitored through the STRIDA project; covered by blanket NPS legislation |

---

## Clinical Trials

**No clinical trials for diphenidine were found in ClinicalTrials.gov.** No registered trials in any jurisdiction are known.

---

## Community Feedback Analysis

**No community feedback was submitted in Part A2 of the brief.** No community feedback to analyze.

---

## Gaps & Flags

### Data Absent from Published Literature

1. **SMILES string** — PubChem CID 206666 contains the canonical SMILES; the API tool did not return it in this run. The generation agent should retrieve it directly from PubChem.

2. **Human pharmacokinetic studies** — No Tmax, bioavailability, half-life, or volume of distribution data from controlled human studies exist. All kinetic data are inferred from animal studies (rat, Wink 2016) or estimated from case concentrations.

3. **Sigma receptor Ki values** — Wallach 2016 confirms moderate sigma-1 and sigma-2 affinity but reports these only in a figure heatmap. The specific Kᵢ is not text-extractable from the abstract or standard PMC full text.

4. **Physical properties** — No published melting point, aqueous solubility, or pKa data found for diphenidine itself (only crystallographic packing data for fluorinated derivatives).

5. **Enantioselective activity** — Diphenidine is a racemate on the market (Euerby 2025), but no study has compared R vs S enantiomer activity at NMDA or other targets.

6. **LD₅₀ / toxic dose** — Not established in any published study for any species.

7. **Bladder toxicity long-term** — Absence of documented bladder toxicity should be framed as absence of evidence, not evidence of absence, given limited long-term user data.

### Safety-Critical Values Requiring Human Review

8. **Tolerance and dependence values in seed DB** — "Physical dependence: moderate," "psychological dependence: moderate," "half-life: 5 days," "full reset: 1.5 weeks" — none of these are confirmed by published primary sources. These appear to be class-based extrapolations. ⚠️ **Flag for editorial review before publication.**

9. **Duration values (seed DB)** — Oral total 2–5 hours, rectal 5–7 hours, smoked 1–3 hours — derived from community reports, not controlled pharmacokinetic studies. WHO ECDD cites effects starting at 50–100 mg, consistent with Community/Light dose range. Duration values are reasonable class estimates but unverified.

### Contradictions Between Sources

10. **First report date** — Mewis et al. 2025 [Ref 17] states diphenidine "was first reported in 2013." The WHO ECDD report and secondary web sources state first synthesis was in 1924 by Christiaen. These are consistent if interpreted as "first reported as an NPS in 2013" vs "first synthesized in 1924." The generation agent should clarify this distinction explicitly.

11. **US scheduling status** — The seed data and some web sources suggest conflicting information about US scheduling. At time of research, diphenidine is NOT formally scheduled under the CSA but is subject to WHO international Schedule II controls adopted in April 2021. The US Federal Register published a 2021 comment request regarding WHO scheduling of diphenidine, but no final US domestic scheduling rule was confirmed.

### Areas Relying on Structural Analogy

12. **Serotonin syndrome risk** — Not substance-specific; inferred from SERT inactivity (>10 μM, Wallach 2016) suggesting low serotonin syndrome risk.

13. **CYP interaction profile** — CYP substrates identified (CYP1A2, CYP2B6, CYP2C9, CYP3A4, CYP2D6 in metabolism), but no data on CYP inhibition or induction by diphenidine itself.

14. **Dependence class inference** — All dependence characterization relies on NMDA dissociative class analogy and one mechanistic study (Sahai 2018 showing DA efflux). No human dependence cases published for diphenidine specifically.

---

## Source Quality Summary

| Category | Best Source | Quality |
|---|---|---|
| Receptor binding pharmacology | Wallach et al. 2016 [Ref 1], PLoS ONE | Strong (peer-reviewed primary research, n=46 receptor sites) |
| Metabolism | Wink et al. 2016 [Ref 4] | Strong (rat + human liver preparations) |
| Clinical toxicology | Helander et al. 2015 [Ref 3] | Moderate (case series, n=17, analytically confirmed) |
| Individual case reports | Gerace et al. 2017 [Ref 14] | Moderate (single case, analytically confirmed) |
| Fatality data | ACMD 2023 [Ref 21] | Moderate (government review, aggregate data) |
| Legal status | Canada Gazette [Ref 22], ACMD 2023 [Ref 21], WHO ECDD [Ref 18] | Strong (official government sources) |
| History | Christiaen 1924 [Ref 23] via WHO ECDD | Weak (unverifiable original source) |
| Dopamine efflux mechanism | Sahai et al. 2018 [Ref 15] | Moderate (in vitro + in silico, rat tissue) |
| Comprehensive review | Katselou et al. 2018 [Ref 27] | Moderate (narrative review, Forensic Toxicology) |