3-MeO-PCP

1-[1-(3-methoxyphenyl)cyclohexyl]piperidine

Overview

3-MeO-PCP belongs to Dissociatives / Arylcyclohexylamines.

Key safety note: 3-MeO-PCP is the most dangerous of the common methoxy/hydroxy phencyclidines in documented harm: it has been implicated in numerous hospitalisations and in deaths (two attributed to 3-MeO-PCP alone and at least fourteen further post-mortem detections reported by 2022, including a UK fatal intoxication).[4][3][2]
Effects
Subjective effects vary. What a substance feels like depends on dose, individual physiology, mindset, and setting. The points below describe commonly reported effects, not guaranteed, uniform, or desirable outcomes.
  • Dissociation, depersonalisation and derealisation. At lower doses users often report comparatively more euphoria, functionality and 'mental clarity' than other dissociatives, which encourages frequent use.
  • Dose-dependent progression to strong dissociation, motor incoordination, internal hallucinations and, at high doses, a dissociative 'hole' with amnesia.
  • Prominent adverse and stimulant-type effects: hypertension, tachycardia, agitation, confusion, paranoia, mania and psychosis, especially at high or repeated doses.
  • Very long-lasting, with a slow onset that frequently leads users to redose too early.
Dosing & duration
Harm-reduction note: These are commonly cited reference ranges, not a recommendation or a “safe” dose. Potency, purity, body chemistry, tolerance, and drug combinations vary widely. Start low, go slow, wait for full effects before redosing, and never assume an unknown product matches these figures. Missing data is not evidence of safety.

Oral, Insufflated. Not a recommendation. 3-MeO-PCP has never been studied in controlled human trials, so these are only commonly cited community ranges. It is exceptionally potent, active in the low single-digit milligram range, and must be dosed with an accurate milligram scale or volumetric solution, never eyeballed. A small error is a large overdose. Its long half-life (≈10–11 h) and slow onset make redosing especially dangerous, and it has a documented record of overdose, psychosis and death.

Dose ranges

Threshold

≈3–5 mg (oral)

Light

≈5–10 mg (oral)

Common

≈10–15 mg (oral)

Strong

≈15–20 mg (oral)

Duration

onset

≈30–90 min (oral)

peak

Not well characterised

total

≈4–12 h (oral)

Chemical & Physical Properties
FormulaC18H27NO
Molar mass273.4 g/mol
StateSolid (usually the hydrochloride salt, white crystalline)
Melting pointNot reported
Boiling pointNot reported
DensityNot reported
Vapor pressureNot reported
pKaNot reported
LogP3.6 (predicted, XLogP3)
SolubilityNot reported
Refractive indexNot reported
Identifiers & Synonyms
CAS72242-03-6
CAS (enantiomer)
PubChem CID11778080
InChIKeyBQQSZHHKGPOXLN-UHFFFAOYSA-N
InChIInChI=1S/C18H27NO/c1-20-17-10-8-9-16(15-17)18(11-4-2-5-12-18)19-13-6-3-7-14-19/h8-10,15H,2-7,11-14H2,1H3
SMILESCOC1=CC=CC(=C1)C2(CCCCC2)N3CCCCC3

Synonyms

  • 3-MeO-PCP
  • 3-Methoxyphencyclidine
  • 3-MeO-Phencyclidine
Pharmacodynamics & Biochemistry

3-MeO-PCP (3-methoxyphencyclidine) is an arylcyclohexylamine dissociative: the 3-methoxy analogue of PCP. It is a high-affinity uncompetitive NMDA-receptor antagonist (Kᵢ ≈20 nM), the most potent NMDA blocker of the common methoxy-arylcyclohexylamines and several-fold more potent than PCP, which drives its dissociative anaesthesia, analgesia and depersonalisation. It additionally inhibits the serotonin transporter (SERT Kᵢ ≈216 nM) and binds the σ1 receptor (Kᵢ ≈42 nM). Unlike 3-MeO-PCE it has no meaningful dopamine- or noradrenaline-transporter activity, and unlike 3-HO-PCP it has no opioid activity, so its effects are those of a potent, long-acting NMDA antagonist with a serotonergic/σ1 component rather than a stimulant or opioid one. Despite lacking direct dopamine-transporter action, 3-MeO-PCP is strongly associated in practice with agitation, mania, paranoia and psychosis and with stimulant-type cardiovascular effects (hypertension, tachycardia). Its high potency and long duration make dangerous overdoses easy, and it has been implicated in a number of hospitalisations and deaths.

Biological targets

  • NMDA
  • SERT
  • Sigma-1

Binding & functional measurements

TargetMeasurementSpecies
NMDA receptorKi 20 nMRat
Serotonin transporterKi 216 nMHuman
Sigma-1 receptorKi 42 nMRodent
DATKi No appreciable activity (contrast with 3-MeO-PCE)Human
NETKi No activity (<50% inhibition at 10 µM)Human
Pharmacokinetics
BioavailabilityOral and insufflated (active by both routes)
TmaxSlow onset ≈30–90 min (oral)
Half-life≈10–11 h (long-acting, estimated)
VdNot reported
Protein bindingNot reported
MetabolismHepatic. O-demethylated to 3-HO-PCP among other metabolites
ExcretionRenal (presumed)
Toxicology & Safety
Harm-reduction note: Toxicity and risk depend on dose, route, purity, combinations, setting, and individual health factors. Missing harms should never be interpreted as evidence of safety.

Not reported

3-MeO-PCP is the most dangerous of the common methoxy/hydroxy phencyclidines in documented harm: it has been implicated in numerous hospitalisations and in deaths (two attributed to 3-MeO-PCP alone and at least fourteen further post-mortem detections reported by 2022, including a UK fatal intoxication). It is extremely potent, oral threshold ≈3–5 mg, strong effects at ≈10–20 mg, so a small weighing or volumetric error is a large overdose, and it must never be eyeballed (a reported 300–500 mg ingestion produced psychosis, aggression and amnesia). Its long half-life (≈10–11 h) and slow onset make delayed, cumulative overdoses easy when users redose. It commonly causes marked agitation, mania, paranoia and psychosis together with hypertension and tachycardia, and dissociation brings the usual dangers of falls, accidents and vomiting with a suppressed gag reflex. Its serotonin-transporter activity adds a serotonin-toxicity risk with other serotonergic drugs, and ketamine-type bladder/urinary-tract damage is a plausible risk of repeated use. It has never been formally studied in humans and the absence of controlled data must not be read as safety.[4][3][2]

Legal Status
Legal note: Legal status can change over time and may vary by country, region, formulation, analogue status, prescription context, and enforcement practice. Always confirm with current official sources before relying on this section.
Interactions & Contraindications

Drug interactions

Alcohol, Benzodiazepines, Opioids, GHB / GBL Additive sedation and impairment, with blackout and aspiration risk.[2]
Stimulants (amphetamines, cocaine) Additive hypertension and tachycardia and a higher risk of agitation and psychosis.[4]
SSRIs, SNRIs, MAOIs Its serotonin-transporter blockade adds a serotonin-toxicity risk.[3]
Other dissociatives (NMDA antagonists) Additive dissociation, with risk of unintended full anaesthesia and immobilisation.[2]

Contraindications

Personal or family history of psychosis, schizophrenia or bipolar disorder 3-MeO-PCP carries a marked psychosis and mania risk.[4]
Cardiovascular disease, hypertension or arrhythmia stimulant-type cardiovascular strain.[2]
Concurrent MAOI, SSRI/SNRI or other serotonergic medication concurrent SSRIs, SNRIs or MAOIs.[3]
Pre-existing bladder or urinary-tract disease, or drug-induced cystitis dissociative uropathy risk with repeated use.[2]
Heavy use: high doses, consecutive days, or mixing with other drugs high doses, consecutive days, using alone, or combined with other drugs.[4]
Usage & Context
  • Sold online as a 'research chemical' / designer dissociative from around 2011. First reported to European monitoring in early 2012 and repeatedly detected in poisonings and deaths thereafter.
  • First synthesised in 1979 during structure–activity studies of phencyclidine. Human effects were documented from the late 1990s.
Sources & Evidence

Further Information