Ephenidine
Ephenidine is a dissociative anesthetic of the diarylethylamine class that acts as an NMDA receptor antagonist.12 It emerged on research chemical markets in early 2015 and has been sold online as a designer drug.21 Structurally related to diphenidine and MXP, ephenidine is widely reported to produce a smoother dissociative experience compared to those compounds.2 Very little is known about this substance, and considerable caution is warranted given the limited safety data available.
Contents
Dosage & Duration
Dosage
Strong tolerance develops rapidly, requiring progressively larger doses to achieve the same effects; tolerance is reported to return to baseline after 1 to 2 weeks of abstinence.
Duration
Subjective Effects
Effects vary widely by individual, dose, and context.
Physical
The subjective physical effects of ephenidine can be broken down into several components which progressively intensify proportional to dosage.
Cognitive
The general head space of ephenidine is often described as particularly euphoric and clear-headed in comparison to that of DXM and ketamine.
Visual
Distortions
Ephenidine exhibits a full array of dissociative distortions and alterations in visual perception.
Geometry
The visual geometry found within ephenidine can be described as very distinct and psychedelic when compared to that of ketamine, MXE, methoxphenidine and diphenidine. It is considerably less detailed than that of DXM. It does not extend beyond level 5 and can be comprehensively described as simplistic in complexity, algorithmic in style, synthetic in feel, unstructured in organization, dimly lit in lighting, multicoloured in scheme, glossy in shading, soft in edges, small in size, slow in speed, smooth in motion, equal in rounded and angular corners, immersive in depth and consistent in intensity.
Hallucinatory States
At high doses, ephenidine can produce a full range of high level hallucinatory states in a fashion that is less consistent and reproducible than that of many other commonly used psychedelics.
Suppressions
Auditory
The auditory effects are common in their occurrence and exhibit a range of effects.
Reagent Testing
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Pharmacology
Pharmacodynamics
Ephenidine acts primarily as an NMDA receptor antagonist with a binding affinity (Ki) of 66.4 nM. It also displays weaker affinity for the dopamine transporter (Ki = 379 nM) and norepinephrine transporter (Ki = 841 nM), as well as sigma-1 (Ki = 629 nM) and sigma-2 (Ki = 722 nM) receptor binding sites.1
Pharmacokinetics
Ephenidine's metabolic pathway involves N-oxidation, N-dealkylation, and hydroxylation of both the benzyl and phenyl rings, with phenyl ring hydroxylation occurring only after N-dealkylation. Dihydroxy metabolites are conjugated by methylation of one hydroxy group, while monohydroxy metabolites undergo glucuronidation or sulfation.
Tolerance
Dissociatives, NMDA receptor antagonists
Harm Potential
Addiction & Dependence
Psychological
Classified as habit-forming with compulsive redosing commonly reported as an effect. The overall addictive potential has not been formally studied and remains unknown.3
Psychosis Risk
At high doses, ephenidine is capable of producing internal hallucinations, warranting due care and attention.
History & Culture
Ephenidine emerged on the research chemical market in early 2015 as a dissociative anesthetic sold through online vendors as a designer drug.4 It was marketed as a potentially smoother alternative to other diarylethylamine dissociatives5 that…
Trip Reports
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Legality
By Country
References
Source Pages
Citations
- (n.d.). Ephenidine: A new psychoactive agent with ketamine-like NMDA receptor antagonist properties. https://doi.org/10.1016/j.neuropharm.2016.06.01712345678
- (n.d.). Ephenidine. The Drug Users Bible. https://drugusersbible.org/content/chemscape/dissociatives/ephenidine/index.html123
- (n.d.). ACMD review of the evidence on the use and harms of diphenidine. 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-accessible12
- (n.d.). Regulations Amending the Food and Drug Regulations (Parts G and J — Lefetamine, AH-7921, MT-45 and W-18). https://gazette.gc.ca/rp-pr/p2/2016/2016-06-01/html/sor-dors106-eng.html12
- (May 2015). Preparation and characterization of the 'research chemical' diphenidine, its pyrrolidine analogue, and their 2,2-diphenylethyl isomers. Drug Testing and Analysis, 7(5), 358–67. https://doi.org/10.1002/dta.16891
- (October 2014). Lefetamine-derived designer drugs N-ethyl-1,2-diphenylethylamine (NEDPA) and N-iso-propyl-1,2-diphenylethylamine (NPDPA): metabolism and detectability in rat urine using GC-MS, LC-MSn and LC-HR-MS/MS. Drug Testing and Analysis, 6(10), 1038–48. https://doi.org/10.1002/dta.16211
Further Reading
ACMD Diphenidine Review (2023)
ACMD Full Report PDF (2023)
Addictovigilance complications (Wiley 2018)
Eiden et al. (2018) - French Addictovigilance Network
Nervewing: Blog - Trip Report (2016)
PubChem: CID 110821 - Ephenidine
Reddit: r/ResearchChemicals - Dosage Survey
ResearchGate: NMDA Binding Data (2016)- Wallach et al. (2016) - Pharmacological Investigations
Automated synthesisInformation aggregated and synthesized using an autonomous workflow built by Josie Kins.
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