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4-MeO-PCP Facts

Dissociative; Arylcyclohexylamine; NMDA receptor antagonist

Description

4-MeO-PCP (4-methoxyphencyclidine) — methoxydine — is a synthetic dissociative of the arylcyclohexylamine class. It is a structural analog of PCP, the original dissociative anesthetic. It blocks glutamate signaling in the brain, producing the heavy disconnection from body and environment characteristic of PCP-type dissociatives.[1]

Subjective effects include heavy sedation, dissociation from body and environment, perceptual distortion, emotional suppression, and depersonalization. The experience is deeply immobilizing — a slow-building disconnection closer to PCP than to the briefer, more stimulating character of 3-MeO-PCP.[2]

Dependence liability parallels PCP; one fatality lists it as the principal cause in a polysubstance context.[3] Two features shape the risk: a slow onset that invites premature redosing, and SERT activity that creates dangerous interactions with common antidepressants.[1]

Dose and durationby route · individual sensitivity varies

Oral(mg)
Threshold< 25 mgLight25 – 50 mgCommon50 – 100 mgStrong100 – 150 mgHeavy250+ mg

Starts in 30 – 90 minLasts 12 – 20 hoursAfter-effects 4 – 12 hours

Body and dependence

Acute toxicity
Moderate
Chronic toxicity
Moderate
Physical dependence
Low
Psychological dependence
Moderate
Withdrawal
Mild
Compulsive redosing
Low

Tolerance

Builds
Moderate
Fully resets after
10 days
Carries over to
PCP; 3-MeO-PCP; ketamine; methoxetamine; dextromethorphan

Effectslikely at a common dose

Perception
none likely · 16 possible, including Spatial disorientation, Vestibular distortion, Visual acuity suppression
Body
Motor control impairment; Sedation; +25 possible, including Dizziness, Insomnia, Nystagmus (eye wobbles)
Thinking
Cognitive impairment; +26 possible, including Memory suppression, Analysis suppression, Confusion
Feeling
none likely · 11 possible, including Anxiety, Emotional lability, Empathy suppression
Self
none likely · 8 possible, including Depersonalization, Derealization, Social disconnection
Time
Time alteration; +1 possible, including Temporal disorientation
Awareness
none likely · 1 possible

Who shouldn't take it

Absolute
Psychotic disorders; Pregnancy
Relative
Cardiovascular disease; Epilepsy; Bipolar disorder; Hepatic impairment; Renal impairment; Concurrent serotonergic medications

Combinations61 recorded

Lethal (2)
GHB, GBL; Ibogaine
Dangerous (35)
Amphetamines; Benzodiazepines; Buprenorphine, Kratom; Ephedrine, Pseudoephedrine; Naltrexone; NDRIs (Wellbutrin); NRIs; NSAIDs; Opioids; THC; Anticholinergics; Antihistamines; Atypical antipsychotics; Benzodiazepines, Barbiturates; Buspirone; Caffeine; Clonidine, Guanfacine; Dopamine agonists; Gabapentin, Pregabalin; GHB, Baclofen; Ketamine, DXM, PCP; Lithium; Local anesthetics; MAOIs; and 11 more, see full page
Caution (21)
See full page: psychedex.org/substances/4-meo-pcp
Not graded (3)
Not listed never means safe.

Seek help immediately if

  • Severe disorientation; unable to move or speak (deep dissociation / "k-hole")
  • Complete loss of coordination — cannot stand or walk safely
  • Vomiting while incapacitated (choking / aspiration risk)
  • Very high blood pressure; fast heart rate
  • Slow or shallow breathing at high doses (especially mixed with depressants)
  • Unconsciousness; rarely, seizures

What to do

  1. Move them somewhere safe, away from stairs, water, roads, and sharp edges — they cannot protect themselves
  2. Place in the recovery position if vomiting or unconscious (aspiration is a key risk)
  3. Stay with them and reassure calmly; keep the environment quiet
  4. If breathing is slow/shallow or they are unresponsive, call emergency services
  5. Do not let them wander; do not leave them alone
  6. Be ready to give rescue breaths / CPR

Effects wear off with time in a safe, monitored setting. The main dangers are physical injury and aspiration while incapacitated, and respiratory depression when combined with other depressants — not the dissociation itself.

988 Suicide & Crisis LifelineFireside Project: 62-FIRESIDE

Version r1 · Not medical advice

References

  1. [1]
    ^abRoth BL, Gibbons S, Arunotayanun W, Huang XP, Setola V, Treble R, Iversen L (2013) The ketamine analogue methoxetamine and 3- and 4-methoxy analogues of phencyclidine are high affinity and selective ligands for the glutamate NMDA receptor — PLoS ONE doi:10.1371/journal.pone.0059334
  2. [2]
    ^Shaw HE, Patel DR, Gannon BM, Fitzgerald LR, Carbonaro TM, Johnson CR, Fantegrossi WE (2024) Phencyclidine-Like Abuse Liability and Psychosis-Like Neurocognitive Effects of Novel Arylcyclohexylamine Drugs of Abuse in Rodents — The Journal of Pharmacology and Experimental Therapeutics doi:10.1124/jpet.123.001942
  3. [3]
    ^McIntyre IM, Trochta A, Gary RD, Storey A, Corneal J, Schaber B (2015) A Fatality Related to Two Novel Hallucinogenic Compounds: 4-Methoxyphencyclidine and 4-Hydroxy-N-methyl-N-ethyltryptamine — Journal of Analytical Toxicology doi:10.1093/jat/bkv089
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