Ephenidine Facts
Dissociative;
Description
Ephenidine (N-ethyl-1,2-diphenylethylamine) — NEDPA, EPE — is a synthetic dissociative of the diarylethylamine class. It blocks glutamate signaling in the brain,[1] cutting off communication between brain regions and producing the dissociative state.
Subjective effects include dissociation, mood lift, physical energy, visual distortions, and cognitive disconnection. The experience is longer and more activating than ketamine — closer in character to PCP, with a warmth and stimulant drive that pure dissociatives lack.[2]
Addictive potential is assessed as highly probable; the class has been linked to 48 deaths globally, one-third involving no other substance.[3]safety citation needed The stimulant-dissociative dual action stacks cardiovascular strain, and opioid co-use adds fatal respiratory risk.[3]
Dose and durationby route · individual sensitivity varies
Starts in 10 – 30 minLasts 5 – 7 hoursAfter-effects 6 – 12 hours
Body and dependence
- Acute toxicity
- Moderate
- Chronic toxicity
- Moderate
- Physical dependence
- Low
- Psychological dependence
- Moderate
- Withdrawal
- None recorded
- Compulsive redosing
- High
Tolerance
- Builds
- Moderate
- Fully resets after
- 10 days
- Carries over to
- ketamine;
phencyclidine; methoxetamine; dextromethorphan; diphenidine; methoxphenidine
Effectslikely at a common dose
- Perception
- none likely · 20 possible, including Spatial disorientation, Vestibular distortion, Visual acuity suppression
- Body
- Motor control impairment;
+28 possible, including Dizziness, Nystagmus (eye wobbles), Nausea - Thinking
- none likely · 26 possible, including Cognitive impairment, Confusion, Memory suppression
- Feeling
- none likely · 7 possible, including Anxiety, Emotional lability, Dysphoria
- Self
- none likely · 9 possible, including Depersonalization, Derealization, Social disconnection
- Time
- none likely · 5 possible, including Temporal disorientation
- Awareness
- none likely · 1 possible
Who shouldn't take it
Combinations61 recorded
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
- Move them somewhere safe, away from stairs, water, roads, and sharp edges — they cannot protect themselves
- Place in the recovery position if vomiting or unconscious (aspiration is a key risk)
- Stay with them and reassure calmly; keep the environment quiet
- If breathing is slow/shallow or they are unresponsive, call emergency services
- Do not let them wander; do not leave them alone
- 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
References
- [1]^Kang H, Park P, Bortolotto ZA, Brandt SD, Colestock T, Wallach J, Collingridge GL, Lodge D (2017) Ephenidine: A new psychoactive agent with ketamine-like NMDA receptor antagonist properties — Neuropharmacology doi:10.1016/j.neuropharm.2016.08.004
- [2]^Eiden C, Leone-Burgos S, Serre A, Carton L, Gerardin M, Le Boisselier R, Gibaja V, Monzon E, Fouilhe N, Boucher A, Peyriere H (2018) Ephenidine, diphenidine, and methoxphenidine complications reported to the French Addictovigilance Network — Fundamental & Clinical Pharmacology doi:10.1111/fcp.12395
- [3]^abCorkery JM, Copeland C, Schifano F (2025) Deaths related to the use of diarylethylamines, with a focus on the United Kingdom: A systematic review and case series report — Journal of Psychopharmacology doi:10.1177/02698811251349203