ketamine, phencyclidine, dextromethorphan +1 moreketamine, phencyclidine, dextromethorphan, nitrous oxide show less
Methoxetamine
MXE (methoxetamine) — Mexxy, Special M — is a synthetic dissociative of the arylcyclohexylamine class. It is a structural derivative of ketamine, modified to be more potent and longer-lasting. It blocks glutamate signaling in the brain and raises serotonin levels,[1] producing dissociation alongside an emotional warmth absent from most dissociatives.[2]
MXE (methoxetamine) — Mexxy, Special M — is a synthetic dissociative of the arylcyclohexylamine class. It is a structural derivative of ketamine, modified for greater potency and longer duration. MXE is a non-competitive NMDA receptor antagonist that also inhibits serotonin reuptake,[1] producing its effects through combined glutamatergic disruption and serotonergic modulation.[2]
ketamine, phencyclidine, dextromethorphan +1 moreketamine, phencyclidine, dextromethorphan, nitrous oxide show less
MXE was first synthesized around 2006 and appeared on online markets in 2010, marketed as a bladder-safe alternative to Ketamine. That claim was contradicted by animal studies showing bladder inflammation and kidney damage,[3][4] and regulators moved quickly. It is now Schedule I in the United States and Class B in the United Kingdom.[5]
Subjective effects include dissociation, depersonalization, pain suppression, emotional enhancement, and internal hallucinations. The experience is warmer and more emotionally present than Ketamine — high doses produce a complete disconnection from surroundings lasting several hours.[2] Anxiety is common at lower doses, and the slow onset frequently leads to premature redosing before the first dose peaks.
Animal studies confirm MXE is habit-forming, and one death has been attributed to it alone;[6] it also produces cross-tolerance with Ketamine, phencyclidine, and similar drugs.[7] Combining it with serotonin-raising drugs risks a dangerous overheating and seizure response, and repeated low-dose exposure causes persistent brain damage in animal models.[8] Almost everything known comes from animal studies and forensic case reports — no human clinical trials have been conducted.
History[edit]
Design and Emergence
MXE was designed around 2006 as a more potent, longer-lasting version of ketamine,[9] with the stated goal of avoiding ketamine's known bladder damage. It first appeared on online research chemical markets in 2010. By late 2010 the EMCDDA had formally flagged it through its Early Warning System.[10]
Market Dissemination
The bladder-safe claim lacked any supporting evidence and was later directly contradicted by animal studies showing bladder inflammation, fibrosis, and kidney damage.[3] Within a year, 58 websites were selling MXE at roughly 145–195 euros per 10 grams,[9] and the substance spread from online vendors into nightlife under the street name "Special M".[11]
Scheduling
Regulatory response was unusually rapid. The UK imposed a temporary ban in April 2012 and permanent Class B classification in February 2013.[12] The UN added it to Schedule II in March 2016,[13] and the United States finalized Schedule I placement in July 2022.[5]
Chemistry[edit]
Structure
Methoxetamine belongs to the arylcyclohexylamine family — the same chemical class as ketamine and phencyclidine.
| Molecular formula | C₁₅H₂₁NO₂ |
| Molecular weight | 247.33 g/mol |
MXE differs from Ketamine at two positions on its molecular structure, making it more fat-soluble and allowing it to penetrate the brain more readily and accumulate there.[14]
This is what makes it more potent than ketamine and accounts for its longer duration. Street-sourced samples have been confirmed as genuine MXE by laboratory analysis.[15]
Pharmacology[edit]
Mechanism of Action
MXE blocks glutamate signaling by lodging inside an open ion channel in the brain — the same fundamental mechanism as ketamine.[1] This disruption of excitatory signaling across the brain drives the core effects: dissociation, pain suppression, and altered consciousness.
Unlike ketamine, MXE also blocks the removal of serotonin from synapses.[1] The resulting serotonin buildup activates emotional and perceptual brain circuits[2] — which is why MXE feels warmer and more emotionally present than a pure dissociative.
Pharmacokinetics
No human pharmacokinetic data exist. In animal studies, MXE accumulates heavily in brain tissue — reaching a brain-to-blood concentration ratio of roughly 2 to 3 throughout the active window[14] — and clears slowly, explaining the long duration. Liver enzymes break it down,[16] and the main metabolite is excreted in urine.[14][17]
Neuroscience[edit]
Where It Acts
MXE disrupts the brain circuits that integrate sensory experience into a coherent sense of reality — the connections between deeper brain structures and the cortex. Blocking glutamate signaling on these circuits generates the disconnected, unreal quality of dissociation.
Why It Matters
MXE also elevates serotonin in the prefrontal cortex and in the brain's mesolimbic pathway.[2] This serotonin boost adds emotional texture and warmth that pure dissociatives lack, and the reward pathway engagement is why MXE is habit-forming.[18]
Rat studies found persistent damage to dopamine and serotonin systems at very low repeated doses[8] — but whether this translates to human-relevant doses is unknown. No human neuroimaging data exist.
Subjective Effects[edit]
MXE produces a dissociative state colored by its serotonergic component.[2] Where ketamine feels clinical and remote, MXE feels warmer — emotionally present, with perceptual distortion woven through a mood that can range from euphoric to anxious. The serotonin layer gives it an emotional richness distinct from any other dissociative.
MXE sits between Ketamine and phencyclidine in the dissociative landscape — stronger and longer-lasting than ketamine, but less stimulating and less aggressive than PCP.[7] Users describe its character as qualitatively unique among NMDA antagonists[20] — the emotional warmth makes it something other than a stronger ketamine.
MXE appeared on online research chemical markets in 2010, marketed as a "bladder-friendly" ketamine alternative — a claim later contradicted by animal studies.[3][4] International scheduling followed rapidly, culminating in UN Schedule II placement in 2016 and US Schedule I in 2022.[5] No human clinical trials have been conducted.
Subjective effects include dissociation, depersonalization, analgesia, and internal hallucinations. The experience is qualitatively distinct from ketamine — warmer, more emotionally textured, and substantially longer — shaped by its unique serotonergic component.[2] Anxiety at low doses, delayed onset inviting dangerous redosing, and prolonged vulnerability during high-dose states are characteristic unsought effects.
No physical dependence has been characterized in humans, but animal models confirm reinforcing properties and cross-tolerance with other NMDA antagonists.[6] One single-substance fatality is documented (post-mortem blood 5.8 µg/mL),[7] and repeated low-dose exposure produces persistent neurotoxicity in rats.[8] The evidence base is predominantly preclinical and forensic — no human pharmacokinetic study, no established lethal dose, and no clinical dependence data exist.
History[edit]
Design and Emergence
Methoxetamine was designed as a longer-acting, more potent modification of ketamine, with the stated intent of avoiding ketamine's dose-limiting bladder toxicity.[9] The compound was first synthesized around 2006, with effects first described on online drug forums in May 2010. By September 2010, MXE was commercially available through "legal high" vendors, and the EMCDDA formally identified it through its Early Warning System in November 2010.[10]
Market Dissemination
MXE spread rapidly through online vendor platforms, with 58 websites selling the compound by mid-2011 at approximately 145–195 euros per 10 grams.[9] It was actively marketed as a safer ketamine alternative — a claim that lacked supporting evidence and was later directly contradicted by animal toxicology studies demonstrating bladder inflammation and fibrosis.[3] Corazza et al. documented MXE's trajectory from online markets into nightlife environments, coining the street name "Special M" as a parallel to ketamine's "Special K".[11]
Scheduling
Regulatory response was unusually rapid. The UK imposed temporary class drug controls in April 2012 and permanent Class B classification in February 2013.[12] The UN Commission on Narcotic Drugs placed MXE in Schedule II of the 1971 Convention in March 2016,[13] and the United States finalized Schedule I placement in July 2022.[5] MXE achieved international scheduling within six years of market emergence — among the fastest trajectories for any novel psychoactive substance in the post-2010 era.
Chemistry[edit]
Structure
Methoxetamine belongs to the arylcyclohexylamine family, sharing the core 2-amino-2-arylcyclohexanone scaffold with ketamine, phencyclidine, and deschloroketamine. The molecule features a cyclohexanone ring with an ethylamino group and a 3-methoxyphenyl ring both attached at the 2-position.
| Molecular formula | C₁₅H₂₁NO₂ |
| Molecular weight | 247.33 g/mol |
MXE differs from ketamine at two positions: the 2-chloro substituent on the phenyl ring is replaced by a 3-methoxy group, and the N-methyl amine is extended to N-ethyl. These changes increase lipophilicity and brain penetrance, contributing directly to MXE's prolonged duration relative to ketamine.
Structure-Activity Relationships
The 3-methoxy substitution (replacing ketamine's 2-chloro) increases lipophilicity and tissue accumulation — the brain:serum ratio exceeds 2.0 throughout the activity window.[14] The N-ethyl extension (from ketamine's N-methyl) further enhances brain penetrance. Together, these modifications produce a compound active at lower doses than ketamine with substantially longer duration.
De Paoli et al. confirmed the structural identity of street-sourced MXE samples via GC-MS and NMR spectroscopy.[15]
Stereochemistry
The C-2 carbon constitutes a chirality centre, producing R(−) and S(+) enantiomers. MXE circulates as the racemic mixture. Botanas et al. demonstrated that the enantiomers differ substantially in abuse potential[16]:
- R(−)-MXE produces antidepressant effects without conditioned place preference or locomotor sensitization — indicating lower abuse liability
- S(+)-MXE produces antidepressant effects but also conditioned place preference and locomotor sensitization — indicating higher abuse liability
Both enantiomers retain NMDA affinity and SERT inhibition.
Pharmacology[edit]
Mechanism of Action
MXE acts as a non-competitive blocker of the NMDA at the phencyclidine binding site, with affinity comparable to or exceeding ketamine.[1] By lodging in the open ion channel, it disrupts glutamate-driven excitatory signalling throughout the brain — the core mechanism producing dissociation, analgesia, and altered consciousness.
Unlike ketamine, MXE simultaneously inhibits the SERT.[1] This dual action has no precedent among clinical dissociative anaesthetics. The resulting serotonin elevation in prefrontal cortex and reward circuitry activates 5-HT₂ receptors, which Marti et al. demonstrated are critical mediators of MXE's motor, sensory, and psychotomimetic effects.[2]
MXE also reduces GABAergic transmission in a concentration-dependent manner without altering baseline glutamate release.[2] The compound enhances mesolimbic dopamine transmission — likely through disinhibition of reward-circuit neurons — which underlies its reinforcing properties.[17]
The antidepressant mechanism mirrors ketamine's: NMDA blockade triggers a compensatory glutamate burst, AMPA activation, and downstream mTOR pathway signalling that promotes rapid synaptic growth.[18][16] The 5-HT₂ receptor system participates in this cascade — blocking it with ketanserin eliminates the antidepressant effect.[18]
Pharmacokinetics
No human pharmacokinetic study has been published. All data derive from animal models or forensic blood concentrations in case reports.
In rats, MXE accumulates preferentially in brain tissue with a brain:serum ratio of 2.06–2.93 throughout the observation window.[14] Brain concentrations peak at approximately 30 minutes post-administration, remain high through 60 minutes, then progressively decline to near-zero by approximately 6 hours. This tissue accumulation and slow release back into circulation explains the extended duration compared to ketamine.
Metabolism proceeds through N-deethylation (via liver enzymes CYP2B6 and CYP3A4), followed by O-demethylation, hydroxylation, and phase II conjugation.[19] The most abundant urinary metabolite is O-desmethylmethoxetamine.[14] Menzies et al. confirmed these metabolic pathways in urine from patients with acute MXE toxicity.[20]
Neuroscience[edit]
Where It Acts
MXE disrupts communication between cortical and subcortical brain regions — the thalamocortical circuits that normally integrate sensory input with higher-order processing. NMDA blockade on inhibitory interneurons paradoxically hyperactivates cortical pyramidal cells, generating the "noise" that manifests as dissociative disconnection. Simultaneously, serotonin elevation in the prefrontal cortex and nucleus accumbens[2] adds an emotional and perceptual dimension absent from pure NMDA antagonists. The mesolimbic dopamine system is also engaged,[17] contributing to reward and reinforcement.
Why It Matters
MXE qualifies as a psychoplastogen — a compound that promotes structural brain plasticity. Both enantiomers activate the mTOR pathway and upregulate AMPA subunits,[16] the same rapid synaptogenesis cascade that underlies ketamine's antidepressant effects. Within predictive processing frameworks, NMDA antagonism disrupts how the brain weights sensory prediction errors, producing the characteristic sense of unreality. MXE's serotonergic component may further modulate this precision-weighting, potentially explaining why users describe its dissociation as qualitatively warmer than ketamine's.
Costa et al. demonstrated persistent dopaminergic and serotonergic neurotoxicity in rats at doses as low as 0.1 mg/kg every other day[8] — but whether this translates to human-relevant doses remains unknown. No human neuroimaging data exist.
Subjective Effects[edit]
MXE produces a dissociative state coloured by its serotonergic dimension — warmer, more emotionally present, and less coldly anaesthetic than ketamine.[2] At low doses, effects lean stimulant and anxiogenic,[14] with perceptual distortion and emotional enhancement. At moderate doses, a deep immersive dissociation develops. At high doses, complete anaesthetic disconnection emerges — the equivalent of ketamine's "hole" but extending over hours rather than minutes. Set and setting strongly modulate the experience across all dose ranges; anxiogenic environments amplify the dysphoric potential.
MXE sits between Ketamine and phencyclidine in the dissociative landscape — longer-acting and more potent by weight than ketamine, but less stimulating and less reinforcing than PCP.[6] The serotonergic contribution distinguishes it from both, lending perceptual and emotional textures that users describe as qualitatively unique among NMDA antagonists.[21]
Effect Grid
At common doses, the full dissociative experience emerges: pronounced depersonalization and derealization, significant disconnection from body awareness, internal hallucinations (geometric patterns, abstract landscapes), and distorted sense of time. Thought processes become non-linear — novel conceptual connections form while sequential reasoning degrades. Analgesia is substantial. Emotional responses may intensify unpredictably.
Physically, marked ataxia makes walking difficult or impossible. Nystagmus, nausea, and numbness throughout the body are typical. Speech becomes significantly impaired. Tachycardia or bradycardia may occur.
Full functional impairment — the user cannot perform tasks requiring coordination or coherent communication. Duration commitment is 4–6 hours with residual effects persisting several hours beyond.
Modeled from the effect's dose-dependence curve — not per-substance measurements.
Proprioceptive distortion · Visual acuity suppression · Touch suppression · Depth perception distortion · Vestibular distortion · Visual drifting · Dreaming enhancement · Auditory distortion · Visual haze / noise · Auditory suppression · Visual processing suppression · Internal hallucinations · Environmental orbism / cubism · Visual scenery slicing · External hallucinations · Auditory hallucinations
Vestibular distortion · Visual drifting · Dreaming enhancement · Auditory distortion · Visual haze / noise · Auditory suppression · Visual processing suppression · Internal hallucinations · Environmental orbism / cubism · Visual scenery slicing · External hallucinations · Auditory hallucinations
Body high · Nystagmus (eye wobbles) · Bodily lightness · Body schema distortion · Muscle relaxation · Tactile euphoria · Sexual arousal suppression · Laughter fits · Tingling / electric sensations · Nausea · Stimulation · Vomiting · Motor control enhancement · Bodily dissociation
Muscle relaxation · Tactile euphoria · Sexual arousal suppression · Laughter fits · Tingling / electric sensations · Nausea · Stimulation · Vomiting · Motor control enhancement · Bodily dissociation
Information processing suppression · Analysis suppression · Introspection enhancement · Thought deceleration · Immersion enhancement · Confusion · Focus suppression · Memory fragmentation · Thought disorganization · Pattern recognition suppression · Conceptual thinking · Language suppression · Creativity enhancement · Humor enhancement · Thought loops · Amnesia · Delusions · Delirium
Thought deceleration · Immersion enhancement · Confusion · Focus suppression · Memory fragmentation · Thought disorganization · Pattern recognition suppression · Conceptual thinking · Language suppression · Creativity enhancement · Humor enhancement · Thought loops · Delusions · Delirium
Anxiety · Dysphoria
Craving · Social disconnection · Sociability suppression · Cognitive disconnection · Ego dissolution · Boundary dissolution · Identity alteration
Ego dissolution · Boundary dissolution · Identity alteration
Timeline
First alerts emerge as subtle bodily lightness and mild perceptual softening. The oral onset is notably slow relative to insufflation, creating significant redosing risk.
Dissociation builds progressively — depersonalization, mild visual distortion, and analgesia become unmistakable. Nausea and ataxia may emerge during this phase.
Maximum dissociative intensity: complete depersonalization, immersive internal visions, loss of time perception, and substantial analgesia. At common doses, communication remains partially possible; at strong doses, full disconnection from external environment.
Dissociation recedes from maximum intensity but remains clearly present. Perceptual distortions continue, cognitive function partially returns. Walking remains impaired.
Gradual return to baseline awareness. Mild perceptual softening and residual numbness persist. Cognitive clarity improves incrementally but full executive function has not returned.
Residual mood alteration, mild cognitive dulling, and slight perceptual differences may persist for 4–12 hours beyond resolution. Sleep quality may be affected.
⚠ Do not drive or operate machinery for at least 12 hours after effects resolve, as residual dissociative impairment and slowed reaction time may persist beyond subjective awareness.
Safety[edit]
- Acute toxicity
- High
- Chronic toxicity
- High
- Withdrawal
- Mild
- Tolerance buildup
- moderate
- Tolerance reset
- 10 days
- Physical
- Low
- Psychological
- Moderate
- Compulsive redosing
- Moderate
- Dose escalation
- Moderate
- Cross-tol.
- ketamine · phencyclidine · dextromethorphan
Toxicity
No lethal dose has been established for MXE in any species. No therapeutic index can be calculated.
Fatalities
One confirmed single-substance death exists, with a post-mortem blood concentration of 5.8 µg/mL.[6] A second case has also been attributed to MXE alone.[21] Combination deaths involving synthetic cannabinoids[22] and amphetamine[23] have been documented.
Brain and Nerve Damage
Repeated low-dose exposure in rats — as little as 0.1 mg/kg every other day, for five doses — caused persistent damage to dopamine and serotonin systems lasting more than a week after the last dose.[8] Animals showed increased anxiety, memory suppression, and altered compulsive behavior. No human brain imaging data exist.
Cerebellar Toxicity
High doses can cause loss of coordination, unsteady walking, and slurred speech — damage to the brain's movement-control center. Three analytically confirmed cases recovered fully with supportive care.[24]
Heart
Documented cardiovascular effects include slowed heart rate (48 bpm), abnormal ECG readings, and low blood sodium.[25] Seizures have occurred during hospitalization.
Bladder and Kidneys
MXE was marketed as a "bladder-friendly" ketamine alternative. Published animal data directly contradict this claim.
Mice given MXE daily for 3 months developed bladder inflammation, fibrosis, and kidney damage.[3] Rat studies confirmed the same pattern — damaged bladder lining, inflammatory infiltration, and scarring comparable to ketamine-induced cystitis.[4] Direct toxic effects on human bladder cells were confirmed in laboratory culture.[4] No published human case of MXE-specific bladder disease exists, but the animal and cell data establish biological plausibility.
Psychological Risks
High-dose MXE produces complete disconnection from reality lasting 4–6 hours — far longer than ketamine's equivalent state — creating extended psychological vulnerability. Anxiety is documented at lower doses in animal models,[14] consistent with human reports.
Repeated exposure impairs memory in animal models, with deficits persisting beyond a week after the last dose.[8] The slow onset — particularly oral — creates conditions for premature redosing, the most commonly reported path to accidental overdose. No data on long-term psychiatric outcomes in humans exist.
Tolerance and Dependence
Animal studies confirm MXE is habit-forming — it produces drug-seeking behavior comparable to ketamine and functions as a reinforcer, though less effectively than PCP.[26][7][18] Cross-tolerance with Ketamine, phencyclidine, and dextromethorphan is confirmed at the glutamate receptor level.[7] No human dependence data have been published.
Drug Interactions
MXE blocks the removal of serotonin from synapses,[1] creating dangerous interactions with any drug that raises serotonin:
- MAOIs (highest severity): Block serotonin breakdown while MXE blocks reuptake — serotonin accumulates to dangerous levels
- SSRIs/SNRIs (including tramadol, venlafaxine): Additive reuptake blockade raises serotonin further
- MDMA: Releases serotonin while MXE blocks its removal — a high-risk combination
CNS depressants compound sedation and suppress protective reflexes:
- Alcohol, GHB/GBL, opioids: respiratory depression and sedation risk
- Synthetic cannabinoids: Documented in a fatal case[22]
The documented MXE and amphetamine death involved extreme body temperature rise, muscle breakdown, and multi-organ failure.[23]
No published MXE serotonin syndrome case has been identified[1] — the risk is inferred from pharmacological mechanism.
Contraindications
8 known- Heart conditions: ECG changes and slowed heart rate documented[25]
- Seizure disorders: Seizure activity documented in cases[25][27]
- Liver impairment: liver enzymes are required to process MXE;[16] impaired clearance expected
- Kidney impairment: Animal studies show kidney toxicity[3]
- Concurrent serotonergic medications: Serotonin overload risk[1]
- Bladder disease history: Animal data show bladder toxicity[3][4]
- Psychotic disorders: psychosis-like effects at all tested doses[28]
Harm Reduction[edit]
Forms & Identification
MXE circulates as a white or off-white crystalline powder. Since international scheduling in 2016 sharply reduced supply, the risk of receiving a mislabelled or substituted product has risen — other arylcyclohexylamines such as deschloroketamine, 2-FDCK, or novel analogues are frequently sold as MXE.
Reagent testing cannot reliably distinguish between arylcyclohexylamine analogues. Laboratory analysis — FTIR or GC-MS through drug checking services — is the only reliable identification method.
A milligram-precision scale is required for accurate dosing. MXE is more potent than ketamine by weight, meaning small measurement errors produce meaningfully different experiences.
Guidelines
- Test the substance — use reagent kits as a first screen, and laboratory drug checking services where available, to rule out dangerous substitutions
- Use a milligram scale — MXE is active at lower doses than ketamine; estimation by eye is unreliable
- Start low, wait long — oral onset can take 60+ minutes; do not redose before 90 minutes have passed. Premature redosing is the most commonly reported path to inadvertent overdose
- Choose one substance — MXE's serotonin reuptake inhibitor creates dangerous interactions invisible until crisis occurs
- Prepare physically — eat lightly beforehand; have water accessible; remove hazards from the environment (sharp edges, stairs, bodies of water)
- Have a sober sitter present — especially at doses approaching the dissociative threshold, where mobility impairment and loss of protective reflexes occur
- Plan for the full duration — ensure 6–8 hours free of obligations, with no need to drive or operate machinery
Set & Setting
MXE's extended duration and dose-dependent dissociation require more environmental preparation than shorter-acting dissociatives. A familiar, physically safe space with soft surfaces reduces injury risk during periods of impaired coordination. An uncomfortable environment can escalate low-dose anxiety into sustained distress.
A sober companion who understands the duration and progression of dissociative states is strongly recommended at moderate-to-high doses, where complete disconnection from surroundings can last for hours.
Aftercare & integration. The day following MXE use commonly involves cognitive sluggishness, mild dissociative residue, and fatigue. Prioritize sleep, hydration, and light nutrition. Avoid demanding cognitive tasks for 24 hours.
Deep dissociative experiences can surface unexpected emotional or existential material. Writing about the experience within 24–48 hours helps process unfamiliar states before they fade. If distressing psychological content persists beyond a few days — depersonalization that won't resolve, intrusive imagery, or persistent anxiety — seek professional support from a therapist familiar with substance-related experiences.
Recovery & Support
MXE's reinforcing properties and cross-tolerance with other dissociatives can support patterns of escalating use. If use has become compulsive, or if tolerance is driving dose increases, the pattern warrants intervention.
Peer support communities focused on dissociative or ketamine recovery provide relevant experience. Professional addiction services can assist with the psychological dimensions. No specific medical withdrawal protocol exists for MXE — a clinician familiar with NMDA antagonist patterns should guide any tapering.
Recovery resources, crisis lines, and support pathways → View all
Emergency Response
Recognizing an emergency:
- Seizure activity (rhythmic jerking, loss of consciousness)
- Extremely slowed heart rate or chest pain
- Inability to rouse the person — unresponsive to voice and touch beyond normal dissociative withdrawal
- High body temperature (skin hot to the touch, sweating profusely)
- Loss of coordination so severe that injury has occurred or is imminent
- Signs of serotonin syndrome (if combined with serotonergic drugs): muscle rigidity, rapid heart rate, agitation, hyperthermia
Immediate steps:
- 1. Call emergency services if seizure, unresponsiveness, chest pain, or high temperature are present
- 2. Place the person in the recovery position if unconscious but breathing
- 3. Do not restrain unless there is immediate danger of self-harm or fall
- 4. Keep the environment calm and dimly lit; reduce sensory input
- 5. Monitor breathing continuously until help arrives or the person becomes responsive
What to tell the dispatcher: Name the substance (methoxetamine / MXE), approximate amount and time taken, current symptoms, and whether other substances were involved. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.
Legal Status[edit]
Methoxetamine is internationally controlled under the United Nations Convention on Psychotropic Substances (Schedule II, 1971 Convention) following the Commission on Narcotic Drugs decision in March 2016.[13]
| Jurisdiction | Classification | Key provisions |
|---|---|---|
| United States | Schedule I (Controlled Substances Act) | Finalized July 6, 2022[5] |
| United Kingdom | Class B (Misuse of Drugs Act 1971) | Temporary class drug April 2012; permanent Class B from February 2013[12] |
| Canada | Schedule I (CDSA analogue) | Controlled from January 2011 under analogue provisions[13] |
| France | Narcotic | Classified August 2013[25] |
| European Union | Controlled (Commission proposal) | Following EMCDDA risk assessment, 2014citation needed |
| Australia | Controlled (analogue provisions) | Scheduled under analogues frameworkcitation needed |
| International (UN) | Schedule II (1971 Convention) | CND 59th Session, March 2016[13] |
Legal status changes over time and varies between jurisdictions. The information above reflects published records and may not be current. This is not legal advice — verify current status before drawing any conclusions about legality in a specific jurisdiction.
Safety[edit]
- Acute toxicity
- High
- Chronic toxicity
- High
- Withdrawal
- Mild
- Tolerance buildup
- moderate
- Tolerance reset
- 10 days
- Physical
- Low
- Psychological
- Moderate
- Compulsive redosing
- Moderate
- Dose escalation
- Moderate
- Cross-tol.
- ketamine · phencyclidine · dextromethorphan
Toxicity
No lethal dose has been established for MXE in any species. No therapeutic index can be calculated.
Fatalities
One confirmed single-substance fatality exists: post-mortem blood concentration of 5.8 µg/mL.[7] A second case (blood MXE 3.6 ng/mL, no other drugs detected) was also attributed to MXE.[22] Polydrug fatalities have been documented with synthetic cannabinoids[23] and amphetamine.[24] MXE was among the most frequently detected novel psychoactive substances in UK forensic casework during 2010–2012.[25]
Brain and Nerve Damage
Repeated low-dose MXE (0.1–0.5 mg/kg every other day, 5 doses) produces persistent damage to dopamine and serotonin systems in rats — reduced transporter density across multiple brain regions lasting 8+ days after the final dose.[8] This manifested as increased anxiety, memory suppression, and altered compulsive behaviour. No human neuroimaging data exist.
Cerebellar Toxicity
High-dose MXE produces a distinctive pattern of reversible cerebellar dysfunction — loss of coordination, unsteady gait, slurred speech — documented in three analytically confirmed cases.[26] All patients recovered fully with supportive care.
Heart
Cardiovascular effects include slowed heart rate (48 bpm documented), ST-segment changes on ECG, and low sodium levels.[27] New seizure activity has occurred during hospitalization.
Bladder and Kidneys
MXE was marketed as a "bladder-friendly" ketamine alternative. Published animal data directly contradict this claim.
Mice given MXE daily for 3 months developed significant bladder inflammation, fibrosis, and kidney damage.[3] Detailed rat studies confirmed damaged bladder lining, inflammatory cell infiltration, and interstitial fibrosis comparable to ketamine-induced cystitis.[4] Direct toxic effects on human bladder cells were confirmed in laboratory culture.[4] No published human case of MXE-specific bladder disease exists, but the animal and human cell data establish biological plausibility.
Psychological Risks
High-dose MXE produces complete disconnection from reality lasting 4–6 hours — far longer than ketamine's equivalent state (30–60 minutes) — creating extended psychological vulnerability. Low doses produce anxiety in animal models,[14] consistent with human reports of dose-dependent anxiogenesis.
Repeated exposure impairs memory in animal models, with deficits persisting beyond a week after the last dose.[8] Sensorimotor gating disruption occurs at all tested doses,[28] indicating psychotomimetic potential. The extended onset — particularly oral — creates a well-documented pattern of premature redosing before initial effects manifest, leading to inadvertent overdose.
No data on MXE-associated persistent perceptual changes, psychosis precipitation, or long-term psychiatric outcomes exist.
Tolerance and Dependence
No published study has characterized MXE tolerance development in humans. MXE substitutes for PCP in drug discrimination and reverses PCP withdrawal signs in rats, confirming cross-tolerance at the NMDA level.[6] Cross-tolerance with Ketamine, phencyclidine, and dextromethorphan is mechanistically expected.
Abuse potential is confirmed: MXE induces conditioned place preference comparable to ketamine and maintains self-administration in rats, though it is a less effective reinforcer than PCP.[29][6][17] No human dependence case series or withdrawal characterization has been published.
Drug Interactions
MXE's SERT inhibition[1] creates serotonin syndrome risk with any co-administered serotonergic agent:
- MAOIs (highest severity): Prevents serotonin breakdown while MXE blocks reuptake
- SSRIs/SNRIs (including tramadol, venlafaxine): Additive reuptake inhibitor
- MDMA: serotonin release combined with reuptake blockade
CNS depressant combinations produce additive sedation and loss of protective reflexes:
- Alcohol, GHB/GBL, opioids: respiratory depression and sedation risk
- Synthetic cannabinoids: Documented in a polydrug fatality[23]
The single documented MXE + amphetamine fatality produced extreme hyperthermia, muscle breakdown, and multi-organ failure.[24]
No published case of MXE-associated serotonin syndrome has been identified[1] — the risk designation is inferred from established pharmacological mechanism.
Contraindications
8 known- Heart conditions: ST-segment changes and slowed heart rate documented[27]
- Seizure disorders: New seizure activity documented in cases[27][30]
- Liver impairment: metabolism depends on CYP2B6/CYP3A4;[19] impaired clearance expected
- Kidney impairment: Animal studies demonstrate renal toxicity[3]
- Concurrent serotonergic medications: Serotonin syndrome risk from SERT inhibition[1]
- Bladder disease history: Animal data demonstrate bladder toxicity[3][4]
- Psychotic disorders: Psychotomimetic effects at all tested doses[28]
Harm Reduction[edit]
Forms & Identification
MXE circulates as a white or off-white crystalline powder in its hydrochloride salt form. Since international scheduling sharply reduced supply after 2016, the risk of receiving mislabelled or substituted product has increased — other arylcyclohexylamines (deschloroketamine, 2-FDCK, or novel analogues) may be sold as MXE. Reagent testing cannot definitively distinguish between arylcyclohexylamine analogues; laboratory analysis (such as FTIR or GC-MS through drug checking services) provides the only reliable identification.
The powder form makes volumetric dosing impractical without a milligram-precision scale. Given MXE's potency relative to ketamine, even small measurement errors produce meaningfully different experiences.
Guidelines
- Test the substance — use reagent kits as a first screen, and laboratory drug checking services where available, to rule out dangerous substitutions
- Use a milligram scale — MXE is active at lower doses than ketamine; estimation by eye is unreliable
- Start low, wait long — oral onset can take 60+ minutes; do not redose before 90 minutes have passed. Premature redosing is the most commonly reported path to inadvertent overdose
- Choose one substance — MXE's serotonin reuptake inhibitor creates dangerous interactions invisible to the user until crisis occurs
- Prepare physically — eat lightly beforehand; have water accessible; remove hazards from the environment (sharp edges, stairs, bodies of water)
- Have a sober sitter present — especially at doses approaching the dissociative threshold, where mobility impairment and loss of protective reflexes occur
- Plan for the full duration — ensure 6–8 hours free of obligations, with no need to drive or operate machinery
Set & Setting
MXE's extended duration (4–6 hours) and dose-dependent dissociation require more environmental preparation than shorter-acting dissociatives. A familiar, physically safe space with soft surfaces reduces injury risk during periods of impaired coordination. The anxiogenic potential at lower doses means that an uncomfortable environment can escalate into sustained distress.
A sober companion who understands the duration and progression of dissociative states is strongly recommended, particularly at moderate-to-high doses where complete disconnection from surroundings can occur for hours.
Aftercare & integration. The day following MXE use commonly involves cognitive sluggishness, mild dissociative residue, and fatigue. Prioritize sleep, hydration, and light nutrition. Avoid demanding cognitive tasks for 24 hours.
Deep dissociative experiences can surface unexpected emotional or existential material. Writing about the experience within 24–48 hours helps process unfamiliar states before they fade or distort in memory. If distressing psychological content persists beyond a few days — depersonalization that won't resolve, intrusive imagery, or persistent anxiety — seek professional support from a therapist familiar with substance-related experiences.
Recovery & Support
MXE's reinforcing properties and cross-tolerance with other dissociatives can support patterns of escalating use. If use has become compulsive, or if tolerance is driving dose increases, the pattern warrants intervention.
Peer support communities (such as those focused on dissociative or ketamine recovery) provide relevant experience. Professional addiction services can assist with the psychological dimensions of compulsive dissociative use. No specific medical withdrawal protocol exists for MXE — tapering guidance should come from a clinician familiar with NMDA antagonist patterns.
Recovery resources, crisis lines, and support pathways → View all
Emergency Response
Recognizing an emergency:
- Seizure activity (rhythmic jerking, loss of consciousness)
- Extremely slowed heart rate or chest pain
- Inability to rouse the person — unresponsive to voice and touch beyond normal dissociative withdrawal
- High body temperature (skin hot to the touch, sweating profusely)
- Loss of coordination so severe that injury has occurred or is imminent
- Signs of serotonin syndrome (if combined with serotonergic drugs): muscle rigidity, rapid heart rate, agitation, hyperthermia
Immediate steps:
- 1. Call emergency services if seizure, unresponsiveness, chest pain, or high temperature are present
- 2. Place the person in the recovery position if unconscious but breathing
- 3. Do not restrain unless there is immediate danger of self-harm or fall
- 4. Keep the environment calm and dimly lit; reduce sensory input
- 5. Monitor breathing continuously until help arrives or the person becomes responsive
What to tell the dispatcher: Name the substance (methoxetamine / MXE), approximate amount and time taken, current symptoms, and whether other substances were involved. Good Samaritan laws in many jurisdictions protect people who call for help during a drug emergency.
Legal Status[edit]
Methoxetamine is internationally controlled under the United Nations Convention on Psychotropic Substances (Schedule II, 1971 Convention) following the Commission on Narcotic Drugs decision at its 59th Session in March 2016.[13] MXE achieved international scheduling within six years of market emergence — among the fastest trajectories for any novel psychoactive substance.
| Jurisdiction | Classification | Key provisions |
|---|---|---|
| United States | Schedule I (Controlled Substances Act) | Finalized July 6, 2022[5] |
| United Kingdom | Class B (Misuse of Drugs Act 1971) | Temporary class drug April 2012; permanent Class B from February 2013[12] |
| Canada | Schedule I (CDSA analogue) | Controlled from January 2011 under analogue provisions[13] |
| France | Narcotic | Classified August 2013[27] |
| European Union | Controlled (Commission proposal) | Following EMCDDA risk assessment, 2014citation needed |
| Australia | Controlled (analogue provisions) | Scheduled under analogues frameworkcitation needed |
| International (UN) | Schedule II (1971 Convention) | CND 59th Session, March 2016[13] |
Schedule I classification in the United States and Class B classification in the United Kingdom preclude legal possession, supply, or manufacture outside licensed research contexts.
Frequently asked questions
What is Methoxetamine?
Methoxetamine is a synthetic arylcyclohexylamine dissociative derived from ketamine, emerging on research-chemical markets around 2010. It acts as an NMDA receptor antagonist with concurrent serotonin reuptake inhibition, a dual mechanism absent in ketamine.
How long does Methoxetamine last?
Total duration by route of administration — Oral: 4 – 6 hours; Insufflated: 3 – 5 hours. Ranges vary with dose and individual factors; see the duration table for onset, peak, and after-effect phases.
Where can I find dosage information for Methoxetamine?
Psychedex publishes a dosage table for Methoxetamine on this page covering these routes of administration: oral, insufflated. Dose values are presented only in that table, always alongside their route of administration.
What are dangerous combinations with Methoxetamine?
The highest-severity documented interactions for Methoxetamine: GHB, GBL (Lethal), 5-HTP, Tryptophan (Dangerous), Alpha-2 adrenergic receptor antagonist (Dangerous), Amphetamines (Dangerous), Anticholinergics (Dangerous). See the interactions section for the full list with mechanisms and severity levels.
Is Methoxetamine addictive?
Psychedex records tolerance and dependence data rather than a yes/no rating. Recorded tolerance indicators for Methoxetamine: tolerance builds moderate; full reset takes 10 days; cross-tolerance develops with ketamine, phencyclidine, dextromethorphan, nitrous oxide. See the article's dependence and safety sections for recorded dependence data.
experience reports
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First-person accounts of subjective effects, timing, and outcomes — submitted for harm reduction.
references
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- [2] ^abcdeMarti M, Talani G, Miliano C, Bilel S, Biggio F, Bratzu J, Diana M, De Luca MA, Fattore L (2021) New insights into methoxetamine mechanisms of action: Focus on serotonergic 5-HT2 receptors in pharmacological and behavioral effects in the rat — Experimental Neurology doi:10.1016/j.expneurol.2021.113836
- [3]
- [4] ^abcdWang Q, Wu Q, Wang J, Chen Y, Zhang G, Chen J, Zhao J, Wu P (2017) Ketamine Analog Methoxetamine Induced Inflammation and Dysfunction of Bladder in Rats — International Journal of Molecular Sciences doi:10.3390/ijms18010117
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- [6] ^abAdamowicz P, Zuba D (2015) Fatal intoxication with methoxetamine — Journal of Forensic Sciences doi:10.1111/1556-4029.12594
references
- [1]
- [2] ^abcdefMarti M, Talani G, Miliano C, Bilel S, Biggio F, Bratzu J, Diana M, De Luca MA, Fattore L (2021) New insights into methoxetamine mechanisms of action: Focus on serotonergic 5-HT2 receptors in pharmacological and behavioral effects in the rat — Experimental Neurology doi:10.1016/j.expneurol.2021.113836
- [3]
- [4] ^abcdWang Q, Wu Q, Wang J, Chen Y, Zhang G, Chen J, Zhao J, Wu P (2017) Ketamine Analog Methoxetamine Induced Inflammation and Dysfunction of Bladder in Rats — International Journal of Molecular Sciences doi:10.3390/ijms18010117
- [5]
- [6] ^abcdBerquist MD, Hyatt WS, Bauer-Erickson J, Gannon BM, Norwood AP, Fantegrossi WE (2018) Phencyclidine-like in vivo effects of methoxetamine in mice and rats. — Neuropharmacology doi:10.1016/j.neuropharm.2017.08.028