O-PCE (2'-oxo-PCE, also called Eticyclidine or 2-oxo-PCE) is a synthetic dissociative of the arylcyclohexylamine class, structurally related to both ketamine (sharing the 2'-oxo cyclohexyl group) and PCE (sharing the N-ethyl substitution). It is among the most potent and widely discussed of the novel dissociatives, with a substantial community experience base documenting a powerful, predominantly NMDA-antagonist dissociation that community members describe as "cold," "analytical," and more overtly PCP-like than ketamine or DCK.
Community documentation of O-PCE is rich and candid. Reports describe a potent dissociative experience that demands careful dose management — one community member describes 15 mg insufflated as producing a dissociation that is "cold" and "analytical" with a character "very different from MXE or DCK." Another post raises the unusual situation of a user who developed an apparent allergic reaction to O-PCE. A thread speculating about O-PCPr (an O-PCE analog) reflects the community's scientific engagement with the structural class. Community warnings about vaping chemicals in general reference O-PCE implicitly.
O-PCE's high potency — active at doses as low as 5–10 mg — combined with its longer duration (3–5 hours) and steep dose-response curve make it one of the more technically demanding dissociatives to use safely. Its effect profile, community members note, is closer to PCP than to ketamine — making it inappropriate for beginners and requiring experienced dissociative users to recalibrate expectations.
Safety at a Glance
High Risk- Treat as High-Potency PCP-Like Compound
- O-PCE requires the harm reduction framework appropriate for a high-potency, PCP-adjacent dissociative — not the light...
- Toxicity: Acute Toxicity: Potency as Primary Risk O-PCE's greatest acute toxicity risk is its potency. At doses only modestly a...
- Dangerous with: Acetylfentanyl, Buprenorphine, Codeine, Desomorphine (+15 more)
- Overdose risk: Overdose on O-PCE can range from unpleasant to life-threatening depending on the dose, route, and...
If someone is in crisis, call 911 or Poison Control: 1-800-222-1222
Dosage
insufflated
oral
Duration
insufflated
Total: 3 hrs – 5 hrsoral
Total: 3 hrs – 6 hrsHow It Feels
The onset announces itself with a gathering coldness — not physical temperature but a psychological chill, a sense that the temperature of consciousness itself is dropping. Within twenty minutes you feel the first stirrings of dissociation: a subtle detachment from the body, a slight hollowing of sound, and a sharpening of visual focus that feels almost predatory. There is no warmth here, no serotonergic embrace. O-PCE enters like a scalpel: precise, clean, and utterly indifferent to your comfort.
The come-up builds steadily over an hour, and the stimulation arrives alongside the dissociation in a combination that is distinctive and somewhat demanding. Your thoughts accelerate but acquire an abstract quality, as though they are being processed by a machine rather than a mind. You can think with unusual clarity about systems, structures, and patterns, but the thoughts feel impersonal, observed from a distance that increases with each passing minute. The body is numb and slightly rigid, as though encased in a form-fitting shell of ice. Movement is possible but feels mechanical, each gesture requiring conscious initiation rather than flowing automatically.
At the peak, O-PCE occupies a unique territory in dissociative space: deeply dissociated yet strangely alert, profoundly detached yet mentally active. Closed-eye visuals are architectural and austere — crystalline structures, infinite grids, spaces rendered in monochrome or cold blues that extend in all directions with mathematical precision. There is a beauty here, but it is the beauty of an empty cathedral in winter: magnificent, severe, and devoid of human warmth. The emotional register is flat but not unpleasant — it is simply absent, as though O-PCE has temporarily disconnected the circuits that assign emotional value to experience. Music sounds extraordinary but in a technical rather than emotional sense: you hear every detail, every nuance of production and arrangement, but it does not move you. It simply is.
The duration is long — six to eight hours, with the stimulation persisting well beyond the dissociative peak. The descent is gradual and marked by a restless, slightly uncomfortable wakefulness. Sleep may be elusive for many hours. The afterglow is mixed: a residual mental clarity coexists with physical tension and a vague sense of depletion. O-PCE does not leave warmth behind. It leaves sharpness — the sense that you have seen something with perfect clarity, even if what you saw was, ultimately, just the crystalline architecture of your own emptied mind.
Subjective Effects
The effects listed below are based on the Subjective Effect Index (SEI), an open research literature based on anecdotal reports and personal analyses. They should be viewed with a healthy degree of skepticism. 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.
Physical Effects
Physical(4)
- Nausea— An uncomfortable sensation of queasiness and stomach discomfort that may or may not lead to vomiting...
- Physical euphoria— An intensely pleasurable bodily sensation that can manifest as waves of warmth, tingling electricity...
- Respiratory depression— A dangerous slowing and shallowing of breathing that can progress from barely noticeable reductions ...
- Stimulation— A state of heightened physical and mental energy characterized by increased wakefulness, elevated mo...
Cognitive & Perceptual Effects
Cognitive(5)
- Amnesia— A complete or partial inability to form new memories or recall existing ones during and after substa...
- Depression— A persistent state of low mood, emotional numbness, hopelessness, and diminished interest or pleasur...
- Paranoia— Irrational suspicion and belief that others are watching, plotting against, or intending harm toward...
- Psychosis— Psychosis is a serious psychiatric state involving a fundamental break from consensus reality — char...
- Wakefulness— An increased ability to stay awake and alert without the desire to sleep. Distinct from stimulation ...
Pharmacology
Mechanism of Action
O-PCE is a potent non-competitive NMDA receptor antagonist. Structural analysis and community dose-effect data indicate it is substantially more potent than ketamine by weight, consistent with a higher NMDA receptor binding affinity. The 2'-oxo (ketone) group on the cyclohexyl ring is shared with ketamine, while the N-ethyl group distinguishes it from ketamine's N-methylamine.
Pharmacological Character
Community descriptions of O-PCE as more "PCP-like" than ketamine-like suggest it may have stronger dopaminergic activity than ketamine — perhaps attributable to the N-ethyl substitution and its effects on the receptor binding profile. The "cold" and "analytical" character contrasts with the warmth of ketamine and MXE, and is consistent with a pharmacology that is more predominantly NMDA antagonist without significant serotonergic or opioid augmentation.
Potency
O-PCE is substantially more potent than ketamine. Community dose references indicate threshold effects at 5–10 mg insufflated and common doses of 10–20 mg, compared to ketamine's 30–75 mg insufflated range. This approximately 3–5x higher potency by weight requires significant downward adjustment for users familiar with other dissociatives.
Duration
Duration is longer than ketamine — typically 3–5 hours for the primary effects, with a prolonged aftereffect period. The combination of high potency and extended duration means that over-dosing produces a long, unpleasant experience that cannot be easily interrupted.
Detection Methods
Standard Drug Panel Inclusion
O-PCE (2-oxo-PCE, deschloroketamine analogue) is NOT included on standard drug screening panels. It does not cross-react with PCP or ketamine immunoassays. Standard 5-panel, 10-panel, and extended panels will not detect this compound.
Urine Detection
O-PCE is detectable in urine for approximately 2 to 5 days after a single dose. The compound is metabolized by N-deethylation, hydroxylation, and glucuronidation. The relatively long duration of action (3 to 5 hours) suggests moderate metabolic stability. Metabolic pathways have been partially characterized through in vitro studies. LC-MS/MS methods specifically targeting O-PCE and its metabolites are required for reliable detection.
Blood and Serum Detection
Blood detection windows are approximately 1 to 3 days. Pharmacokinetic data is limited to case reports and in vitro studies. Forensic cases involving O-PCE have been documented, providing some blood concentration data, with impairment-related concentrations typically in the tens to hundreds of nanograms-per-milliliter range.
Hair Follicle Detection
Hair analysis for O-PCE is feasible with LC-MS/MS methods but has not been widely validated. The compound's basic, lipophilic properties favor hair incorporation.
Confirmatory Methods
LC-MS/MS provides definitive identification. The arylcyclohexylamine structure produces characteristic mass spectral fragmentation patterns. GC-MS is also applicable. Reference standards are available from forensic and research chemical suppliers.
Reagent Testing
The Marquis reagent produces no reaction with O-PCE. The Mandelin reagent may produce a faint orange color. The Morris reagent may produce a color change characteristic of arylcyclohexanone compounds. Fentanyl test strips should be used on all products from unregulated sources.
Interactions
| Substance | Status | Note |
|---|---|---|
| Acetylfentanyl | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Buprenorphine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Codeine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Desomorphine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Dextropropoxyphene | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Dihydrocodeine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Ethylmorphine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Fentanyl | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Heroin | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Hydrocodone | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Hydromorphone | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Kratom | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Methadone | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Morphine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Naloxone | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| O-Desmethyltramadol | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Oxycodone | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Oxymorphone | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| Pethidine | Dangerous | Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration |
| 1,4-Butanediol | Caution | Both cause CNS depression; increased risk of vomiting, unconsciousness, and respiratory depression |
| 2-Fluorodeschloroketamine | Caution | Compounding dissociative effects can cause confusion, mania, and loss of motor control |
| 2M2B | Caution | Both cause CNS depression; increased risk of vomiting, unconsciousness, and respiratory depression |
| 3-Cl-PCP | Caution | Compounding dissociative effects can cause confusion, mania, and loss of motor control |
| 3-HO-PCE | Caution | Compounding dissociative effects can cause confusion, mania, and loss of motor control |
| 1,3-Butanediol | Low Risk & Synergy | Produces unique synergistic effects; often combined |
| 1B-LSD | Low Risk & Synergy | Produces unique synergistic effects; often combined |
| 1cP-AL-LAD | Low Risk & Synergy | Produces unique synergistic effects; often combined |
| 1cP-LSD | Low Risk & Synergy | Produces unique synergistic effects; often combined |
| 1cP-MiPLA | Low Risk & Synergy | Produces unique synergistic effects; often combined |
History
Development
O-PCE's structural design combines the 2'-oxo group of ketamine with the N-ethyl group of PCE. This reflects the systematic SAR exploration of arylcyclohexylamines that has generated dozens of analogs across several decades of pharmaceutical and research chemical chemistry. The specific combination producing O-PCE was likely synthesized during the mid-20th century pharmacological research era and rediscovered or resynthesized for the research chemical market.
Research Chemical Era
O-PCE became prominent in the research chemical dissociative market during the 2010s, particularly as other compounds were scheduled. Its potency and distinct PCP-adjacent character attracted experienced dissociative users seeking novel pharmacological territory. Community documentation is extensive and includes detailed dose-effect mapping, comparative reports against other dissociatives, and specific harm reduction discussions.
Scientific Interest
O-PCE's structural position as a ketamine-ketone + PCE-ethyl hybrid makes it pharmacologically interesting for SAR research. Community discussions have extended to speculation about related structures (O-PCPr) — reflecting the scientifically curious component of the research chemical community.
Legal Status
O-PCE falls under analogue legislation in many jurisdictions given its structural relationship to ketamine and PCE. It is explicitly scheduled in some countries, and the legal status varies and continues to evolve.
Harm Reduction
Treat as High-Potency PCP-Like Compound
O-PCE requires the harm reduction framework appropriate for a high-potency, PCP-adjacent dissociative — not the lighter framework appropriate for ketamine:
- A sober companion is strongly recommended for any dose above threshold
- Physical environment must be completely secured — inability to fall, remove hazardous objects
- Do not drive or operate machinery within 8–10 hours of use
Start Extremely Low
Given 3–5x higher potency than ketamine:
- Start at 5 mg or less (insufflated) for a test dose
- Wait the full 3–5 hour duration before any assessment of the experience
- Do not redose during the primary experience
Volumetric Dosing
At the dose ranges involved (5–20 mg), powder dosing from a scale introduces unacceptable margin of error for many users. Volumetric dosing from a weighed stock solution in ethanol or water allows more precise dose delivery.
Avoid Vaporization
Vaporizing O-PCE or any novel research chemical produces unknown pyrolysis products. Insufflation or oral administration are the community-established routes with more safety data.
Allergic Reaction Awareness
The documented allergic response report warrants awareness. If unusual symptoms (rash, swelling, difficulty breathing) occur during an O-PCE experience, treat as an allergic reaction requiring emergency medical attention.
Toxicity & Safety
Acute Toxicity: Potency as Primary Risk
O-PCE's greatest acute toxicity risk is its potency. At doses only modestly above a comfortable recreational amount, O-PCE produces overwhelming dissociation that community members describe as frightening and completely destabilizing. The margin between a manageable experience and a genuinely distressing one is narrow, and the long duration means that a miscalculated dose cannot be quickly resolved.
Respiratory Risk
At very high doses, all arylcyclohexylamines can produce respiratory depression. O-PCE's potency makes reaching these doses easier than with less potent compounds, particularly if users apply ketamine-scale dose references.
Psychological Risks
- Acute panic and terror — community accounts describe overwhelmingly intense experiences at higher doses that can be genuinely traumatizing
- Paranoia and psychosis-like states — the PCP-like character elevates this risk compared to ketamine
- Difficult integration — very high-dose O-PCE experiences may require time and support to process
Vaporization Risks
Community discussion of vaporizing O-PCE reflects general concerns about vaporizing research chemicals — pyrolysis products and lung irritation from concentrated compound exposure. Standard harm reduction advice against vaporizing unknown research chemicals applies.
Allergic Reactions
At least one community report documents an apparent allergic response to O-PCE — a reminder that individual idiosyncratic reactions are possible with any compound, particularly novel ones without extensive human exposure data.
Addiction Potential
moderately addictive with a high potential for abuse
Overdose Information
Overdose on O-PCE can range from unpleasant to life-threatening depending on the dose, route, and whether other substances are involved.
Signs of overdose: Severe nystagmus, complete unresponsiveness, vomiting (aspiration risk while unconscious), severely depressed breathing, seizures, extremely elevated heart rate or blood pressure.
Critical dangers:
- Respiratory depression: Particularly when combined with other depressants
- Aspiration: Loss of protective reflexes combined with nausea creates choking risk
- Hyperthermia or hypothermia: Impaired thermoregulation at high doses
Emergency response: Place the person in the recovery position. Monitor breathing. Call emergency services if breathing is slow, shallow, or irregular; if the person is unresponsive to stimulation; or if seizures occur. Be honest with medical personnel about what was consumed — they are there to help, not to judge.
Dangerous Interactions
The combinations listed below may be life-threatening. Independent research should always be conducted to ensure safety when combining substances.
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Both cause respiratory depression and unconsciousness; vomiting while dissociated risks aspiration
Tolerance
| Full | develops with prolonged and repeated use |
| Half | 3 - 7 days |
| Zero | 1 - 2 weeks |
Cross-tolerances
Legal Status
Czech Republic:** O-PCE is a Schedule I (List 4) substance. It may be used for research and restricted therapeutic purposes.
Germany:** 2-Oxo-PCE is controlled under the NpSG (New Psychoactive Substances Act) as of July 18, 2019. Production and import with the aim to place it on the market, administration to another person and trading is punishable. Possession is illegal but not penalized.
The Netherlands:** O-PCE is currently not illegal in the Netherlands, and is sold as a research chemical.
Switzerland:** O-PCE is a controlled substance specifically named under Verzeichnis E.
United Kingdom** - 2-Oxo-PCE is a class B drug in the UK and is illegal to possess, produce, supply, or import. As an N-alkyl derivative of 2-Amino-2-phenylcyclohexanone, 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.
Responsible use
Research chemical
Dissociative
O-PCM
2'-Oxo-PCE (Wikipedia)
O-PCE (Isomer Design)
2-Oxo-PCE (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
Experience Reports (2)
Tips (10)
Never use O-PCE near water (bathtubs, pools, lakes). Dissociation and water are a deadly combination. Loss of body coordination and awareness while near water has caused drownings.
If insufflating O-PCE, start with a small bump and wait 15-20 minutes to assess effects before taking more. Onset via insufflation is faster than oral, but full effects still take time to manifest.
Choose a safe physical environment before using O-PCE. Remove sharp objects, secure stairs, and create a comfortable space to lie or sit. Dissociation makes spatial awareness unreliable and falls are common.
O-PCE is significantly more potent by weight than ketamine or DCK. Start with 5-10mg and wait at least 90 minutes before redosing. It has a long onset that catches many users off guard.
Some users develop an allergic reaction to O-PCE that manifests as a morbilliform rash spreading across the body. This can develop after initial use without problems. If you notice any rash, discontinue immediately.
O-PCE combined with other dissociatives or depressants significantly increases risk of respiratory depression and prolonged dissociative states. Keep O-PCE sessions simple and avoid polydrug combinations until you know exactly how it affects you.
Community Discussions (8)
See Also
References (3)
- Ketamine as a rapid antidepressant — Berman et al. Biological Psychiatry (2000)paper
- O-PCE - TripSit Factsheet
TripSit factsheet for O-PCE
tripsit - O-PCE - Wikipedia
Wikipedia article on O-PCE
wikipedia