4-MeO-PCP

4-MeO-PCP, or 4-Methoxyphencyclidine, is a synthetic dissociative of the arylcyclohexylamine class. 4-MeO-PCP contains cyclohexane, a six member saturated ring, bonded to two additional rings at R₁. One of these rings is a piperidine ring (a nitrogenous six member ring) bonded at its nitrogen group. The other ring is an aromatic phenyl ring substituted at R₄ with a methoxy group. 4-MeO-PCP is a PCP derivative, and structurally analogous to 3-MeO-PCP.

4-MeO-PCP acts as an NMDA receptor antagonist. NMDA receptors allow for electrical signals to pass between neurons in the brain and spinal column; for the signals to pass, the receptor must be open. Dissociatives close the NMDA receptors by blocking them. This disconnection of neurons leads to loss of feeling, difficulty moving, and eventually an almost identical equivalent of the famous “k-hole.”

4-MeO-PCP has lower affinity for the NMDA receptor than PCP, but higher affinity than ketamine. It is orally active in a dosage range similar to ketamine with some users requiring doses in excess of 100mg for desired effects.^[3][1] Users have reported substantial differences in active dose; these discrepancies can be partially explained by the presence of unreacted PCC and other impurities in samples sold on the grey market.^[1] Though 4-MeO-PCP has been suggested to possess dopaminergic activity, it is a relatively selective ligand for the NMDA receptor without appreciable affinity for the dopamine transporter.^[3]

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWiki contributors. As a result, they should be viewed with a healthy degree of skepticism.

It is also worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.

Experience reports

There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:

• Erowid Experience Vaults: 4-MeO-PCP

Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).

Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.

• Stimulants - Both stimulants and dissociatives carry the risk of adverse psychological reactions like anxiety, mania, delusions and psychosis and these risks are exacerbated when the two substances are combined.
• Depressants - Because both depress the respiratory system, this combination can result in an increased risk of suddenly falling unconscious, vomiting and choking to death from the resulting suffocation. If nausea or vomiting occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.

The toxicity and long-term health effects of recreational 4-MeO-PCP use do not seem to have been studied in any scientific context and the exact toxic dosage is unknown. This is because 4-MeO-PCP has very little history of human usage. Anecdotal evidence from people who have tried 4-MeO-PCP within the community suggest that there do not seem to be any negative health effects attributed to simply trying this drug at low to moderate doses by itself and using it sparingly (but nothing can be completely guaranteed). Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.

It is strongly recommended that one use harm reduction practices when using this drug.

Tolerance and addiction potential

As with other NMDA receptor antagonists, the chronic use of 4-MeO-PCP can be considered moderately addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal effects may occur if a person suddenly stops their usage.

Tolerance to many of the effects of 4-MeO-PCP develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). 4-MeO-PCP presents cross-tolerance with all dissociatives, meaning that after the consumption of 4-MeO-PCP all dissociatives will have a reduced effect.

Dangerous interactions

Warning: Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).

Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.

• Stimulants - Both stimulants and dissociatives carry the risk of adverse psychological reactions like anxiety, mania, delusions and psychosis and these risks are exacerbated when the two substances are combined.
• Depressants - Because both depress the respiratory system, this combination can result in an increased risk of suddenly falling unconscious, vomiting and choking to death from the resulting suffocation. If nausea or vomiting occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.

Urinary tract effects

In terms of its long-term health effects when used repeatedly and with excess for extended periods of time, 4-MeO-PCP seems to exhibit almost identical bladder and urinary tract problems to those found within ketamine but to a lesser extent. This is because 4-MeO-PCP is a little more potent than ketamine, meaning that less of the drug needs to be consumed. Symptoms of ketamine-induced cystitis can become extremely serious and can be described as:

• Urinary frequency - Urinary frequency is the need to empty the bladder every few minutes.
• Urinary urgency - This can be described as a sudden, compelling need to urinate.
• Urinary pressure - This is experienced as a constant sensation of fullness in the bladder that is unrelieved by urination.
• Pelvic and bladder pain - Pain can develop suddenly and severely, particularly as the bladder fills with urine.
• Hematuria - Hematuria is visible blood in the urine.
• Incontinence - This is the leakage of urine.

All of these, however, can easily be avoided by simply not using 4-MeO-PCP on a daily or even weekly basis and manually limiting one's usage of the substance.

• Germany: 4-MeO-PCP is a controlled substance under the NpSG since 27th September 2021^[4].
• Sweden - Sweden's public health agency suggested classifying 4-MeO-PCP as a hazardous substance on November 10, 2014.^[5]
• Switzerland: 4-MeO-PCP is a controlled substance specifically named under Verzeichnis E.^[6]
• Turkey: 4-MeO-PCP is a classed as drug and is illegal to possess, produce, supply, or import.^{[7] [8]}
• United Kingdom - 4-MeO-PCP is a class B drug in the UK and is illegal to possess, produce, supply, or import. As a derivative of 1-Phenylcyclohexylamine where the amine has been replaced with a 1-piperidyl group, further substituted in the phenyl ring with an alkoxy substituent, it is covered by the arylcyclohexylamine generic clause added to the Misuse of Drugs Act by S.I. 2013/239, which came into effect on the 26th February 2013.^[9]

• Responsible use
• Research chemical
• Dissociatives
• Arylcyclohexylamines
• 3-MeO-PCP
• PCP

• 4-MeO-PCP (Wikipedia)
• 4-MeO-PCP (Erowid Vault)
• 4-MeO-PCP (Isomer Design)
• 4-MeO-PCP (Bluelight)
• Interview with a Ketamine Chemist (VICE)

• Morris, H., & Wallach, J. (2014). From PCP to MXE: A comprehensive review of the non-medical use of dissociative drugs. Drug Testing and Analysis, 6(7–8), 614–632. https://doi.org/10.1002/dta.1620