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Methoxphenidine

Methoxphenidine molecule structureMethoxphenidine molecule structure

Methoxphenidine is a dissociative substance of the substituted diarylethylamine class1 that is anecdotally reported by human users to produce dissociative effects.1 It was originally patented in 19892 and entered recreational markets in late 2013.3 Reports suggest it has greater oral potency than diphenidine and effects that differ from methoxetamine. Its effects are reported to be unpredictable, and it can cause blackouts. The hydrochloride salt is also reported to raise blood pressure.

Dosage & Duration

Dosage

Doses are population estimates that vary widely between individuals.

Threshold30-50 mg
Light50-75 mg
Moderate75-120 mg
Strong120-150 mg
Heavy200+ mg

Duration

Onset30-60 minutes
After Effects1-3 hours
Total6-8 hours

Subjective Effects

Legacy content. A statistically backed ontology from Mindstate Design Labs is coming soon.

Effects vary widely by individual, dose, and context.

Physical

Physical autonomyDizziness

Cognitive

The head space of MXP is often described as particularly clear headed even at heavy dosages. It is far more controllable, less disorientating and confusing at dosages of equal subjective intensity to that of MXE, DXM and Ketamine.

Consciousness disconnectionAcceleration of thoughtEgo suppression, loss and deathEuphoriaConceptual thinking

Visual

Hallucinatory States

Auditory

The auditory effects of MXP are common in their occurrence but unlike other more commonly used dissociatives, they are unlikely to suppress or distort auditory input.

Enhancements
Forked from Subjective Effect Documentation byJosie Kins March 2014.

Pharmacology

Pharmacodynamics

Methoxphenidine acts as an NMDA receptor antagonist.4 Dopamine reuptake inhibition has also been suggested from anecdotal reports, but this mechanism has not been formally studied.

Pharmacokinetics

The freebase is insoluble in water and is reported to convert to the hydrochloride salt in the stomach after oral administration. Preparing the citrate salt is reported to improve absorption.

Metabolitesnone documented yet

Interactions

Interactions not written up yet

An unlisted combination is an unknown one, not a safe one. Check a dedicated combination chart before mixing.

Check TripSit

Tolerance

Tolerance timelines are rules of thumb, not exact schedules, and vary widely between individuals and use patterns.

Full Tolerance
Methoxphenidine produces substantial tolerance, with increasingly large doses required to achieve the same intensity of effects; the time to full tolerance is unspecified. Preparing the citrate salt with citric acid or lemon juice may mitigate tolerance by improving absorption and increasing effects.
Baseline Reset
Tolerance is expected to return to baseline after 1–2 weeks.

Harm Potential

Addiction & Dependence

Psychological

Methoxphenidine is described as habit-forming, although its addictive potential remains uncertain.

Physical

Strong tolerance has been described with methoxphenidine use, requiring progressively larger doses to obtain the same effects.

Toxicity

Lethal Dosage

Methoxphenidine use has been associated with three published fatalities.5

Cardiovascular

Acute methoxphenidine intoxication has produced hypertension and tachycardia.4

Nervous system

Confusion was reported in an acute intoxication case in which methoxphenidine was detected.4

Psychosis Risk

Psychotic episodes have been reported with methoxphenidine use, including an episode associated with a murder in June 2014.

Seizure Risk

A personal account recalls internet reports of seizures following high doses of methoxphenidine.

History & Culture

Methoxphenidine was first reported in a 1989 patent,7 in which it was tested as a potential treatment for neurotoxic injury.…

Legality

International

Legal grey area

References

Citations

  1. Pharmacological Investigations of the Dissociative ‘Legal Highs’ Diphenidine, Methoxphenidine and Analogues. PLOS ONE (2016). https://doi.org/10.1371/journal.pone.015702112
  2. Intriguing Cytotoxicity of the Street Dissociative Anesthetic Methoxphenidine: Unexpected Impurities Spotted. International Journal of Molecular Sciences (2022). https://doi.org/10.3390/ijms230420831
  3. From PCP to MXE: a comprehensive review of the non-medical use of dissociative drugs. Drug Testing and Analysis (2014). https://doi.org/10.1002/dta.16201
  4. ACMD review of the evidence on the use and harms of diphenidine (accessible). GOV.UK (2023). https://www.gov.uk/government/publications/acmd-review-of-the-evidence-on-the-use-and-harms-of-diphenidine/acmd-review-of-the-evidence-on-the-use-and-harms-of-diphenidine-accessible123
  5. First Reported Fatalities Associated with the 'Research Chemical' 2-Methoxydiphenidine. Journal of Analytical Toxicology (2015). https://doi.org/10.1093/jat/bkv0061
  6. 2-MEO-diphenidine: Critical Review Report. World Health Organization (2020). https://cdn.who.int/media/docs/default-source/controlled-substances/43rd-ecdd/2-meo-diphenidine-report-final-a.pdf?sfvrsn=7fe2b600_41
  7. Acute toxicity associated with the recreational use of the novel dissociative psychoactive substance methoxphenidine. Clinical Toxicology (2014). https://doi.org/10.3109/15563650.2014.9742641
  8. Pharmacological investigations of the dissociative “Legal Highs” diphenidine, methoxphenidine and analogues. PLOS ONE (2016). https://doi.org/10.1371/journal.pone.01570211
  9. Word of Mouse: Indigenous Harm Reduction and Online Consumerism of the Synthetic Compound Methoxphenidine. South East Technological University (2015). https://doi.org/10.1080/02791072.2014.9740021

Further Reading

  1. Luethi et al. 2018 - Effects of the new psychoactive substances diclofensine, diphenidine, and methoxphenidine on monoaminergic systems

Article Status

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