This is an unofficial archive of PsychonautWiki as of 2025-08-08T03:33:20Z. Content on this page may be outdated, incomplete, or inaccurate. Please refer to the original page for the most up-to-date information.
WARNING: Always start with lower doses due to differences between individual body weight, tolerance, metabolism, and personal sensitivity. See responsible use section.
DISCLAIMER: PW's dosage information is gathered from users and resources for educational purposes only. It is not a recommendation and should be verified with other sources for accuracy.
Ephenidine (also known as NEDPA and EPE) is a lesser-known novel dissociative substance of the diarylethylamine class. Ephenidine is an NMDA receptor antagonist[1] that is structurally related to diarylethylamines like diphenidine and methoxphenidine. Notable effects include sedation, hallucinations, anesthesia, and out-of-body states, referred to as "dissociative anesthesia".
Ephenidine and related diarylethylamines have been studied in humans as treatments for neurotoxic injuries.[2][3][4][5][6]
Recreational use was not documented until the 2013 U.K. arylcyclohexylamine ban, when it was released on the online research chemical market.[7] It was marketed alongside diphenidine and methoxphenidine as a substitute for methoxetamine (MXE) despite users claiming markedly different effects.
Very little data exists about the pharmacological properties, metabolism, and toxicity of ephenidine, and it has an extremely limited history of human usage. The abuse of diarylethylamines has been linked to a number of fatal and non-fatal overdoses.[1] Many reports suggest that they may pose different risks than traditional dissociatives. It is highly advised to use harm reduction practices if using this substance.
As a result, it may contain incomplete or wrong information. You can help by expanding it.
Ephenidine has been described as a designer drug. Designer drugs are substances mimic the functional and structural features of commonly used illicit substances in order to circumvent government regulation.[8][9]
Chemistry
Ephenidine is a molecule of the diarylethylamine class. It contains a substituted phenethylamine skeleton with an additional phenyl ring bound to Rα. An ethyl chain is bound to the terminal amine RN of the phenethylamine. Ephenidine is structurally analogous to diphenidine and MXP, but is not a piperidinedissociative. Ephenidine shares a diphenylethylamine skeleton with diphenidine and MXP, but lacks a piperidine substitution.
Ephenidine acts as an antagonist of the NMDA receptor (Ki = 66.4 nM).[10][11][12][13][14] The NMDA (N-methyl-D-aspartate) receptor is one of the major receptor subtypes for glutamate, the major excitatory neurotransmitter in the central nervous system (CNS). When NMDA channels are blocked, a loss of feeling (anesthesia), difficulty moving (immobilization), and at higher doses, the compound's equivalent of the “K-hole” results.
Ephenidine also possesses weaker affinity for the dopamine and norepinephrine transporters (379 nM and 841 nM, respectively) as well as σ1R (629 nM) and σ2R (722 nM) binding sites.[15]
Subjective effects
Ephenidine is reported to have a much more rapid onset and lower half-life when vaporized or smoked. When consumed this way, it is a suspected to be carcinogenic when excess heat is used. Some user reports have concluded that vaporization and plugging requires as low as 20% of what would be a common oral dose for that person.
Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), an open research literature based on anecdotal user reports and the personal analyses of PsychonautWikicontributors. As a result, they should be viewed with a healthy degree of skepticism.
It is also worth noting that 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. Likewise, adverse effects become increasingly likely with higher doses and may include addiction, severe injury, or death ☠.
Spontaneous physical sensations - The ephenidine "body high" is a soft and pleasurable tingling sensation which is motionless and all-encompassing with no specific location.
Tactile suppression - This partially to entirely suppresses one's sense of touch, creating feelings of numbness within the extremities. It is responsible for the anaesthetic properties of this substance.
Motor control loss - A loss of gross and fine motor control alongside of balance and coordination is prevalent within the ephenidine experience and becomes especially strong at higher doses. This means that one should be sitting down before the onset (unless one is experienced) in case of falling over and injuring oneself.
Perception of bodily lightness - This creates the sensation that the body is floating and has become entirely weightless. This effect is strangely stimulating and encourages physical activities at low to moderate doses by making the body feel light and effortless to move.
Gait alteration - Ephenidine typically causes movement such as walking to be perceived as automated and robotic.
Visual disconnection - This eventually results in the ephenidine equivalent of the famous "k-hole" or, more specifically, holes, spaces and voids alongside of structures. However, it is worth noting that particularly heavy doses must be consumed to reach the deepest state of this component in comparison to other more classical dissociatives such as ketamine or methoxetamine.
Double vision - This component is prevalent at moderate to heavy dosages and makes reading impossible unless one closes an eye.
Pattern recognition suppression - This effect generally occurs at higher dosages and makes one unable to recognize and interpret perceivable visual data.
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 through its variations 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. These effects include:
The general head space of ephenidine is often described as particularly euphoric and clear-headed in comparison to that of DXM and ketamine. The specific cognitive effects can be broken down into several separate subcomponents which are listed and described below:
Time distortion - This creates the illusion of time passing much more slowly than it would while sober. For example, a user could perceive that an hour or several hours have passed, over the course of only a few minutes.
The toxicity and long-term health effects of recreational ephenidine use do not seem to have been studied in any scientific context and the exact toxic dosage is unknown. This is because ephenidine has very little history of human usage.
Anecdotal reports from those who have tried ephenidine suggest that there do not seem to be any negative health effects attributed to simply trying this drug at low to moderate doses by itself and using it sparingly (but nothing can be completely guaranteed). Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.
As with other NMDA receptor antagonists, the chronic use of ephenidine can be considered moderately addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal effects may occur if the user suddenly stops their usage.
Tolerance to many of the effects of ephenidine develops with prolonged and repeated use. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 - 7 days for the tolerance to be reduced to half and 1 - 2 weeks to be back at baseline (in the absence of further consumption). Ephenidine presents cross-tolerance with [[Cross-tolerance::all dissociatives]], meaning that after the consumption of ephenidine all dissociatives will have a reduced effect.
Dangerous interactions
Warning:Many psychoactive substances that are reasonably safe to use on their own can suddenly become dangerous and even life-threatening when combined with certain other substances. The following list provides some known dangerous interactions (although it is not guaranteed to include all of them).
Always conduct independent research (e.g. Google, DuckDuckGo, PubMed) to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit.
Stimulants - Both stimulants and dissociatives carry the risk of adverse psychological reactions like anxiety, mania, delusions and psychosis and these risks are exacerbated when the two substances are combined.
Depressants - Because both depress the respiratory system, this combination can result in an increased risk of suddenly falling unconscious, vomiting and choking to death from the resulting suffocation. If nausea or vomiting occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
As such, it may contain incomplete or wrong information. You can help by expanding it.
Ephenidine is illegal in some countries as a structural isomer of the banned opioid drug lefetamine.[16][17]
Canada: As of March 2016, MT-45 and its analogues, one of which being ephenidine, are Schedule I controlled substances.[18] Possession without legal authority can result in maximum 7 years imprisonment. Only those with a law enforcement agency, person with an exemption permit or institutions with Minister's authorization may possess the drug.
Germany: Ephenidine is a controlled substance under the NpSG (New Psychoactive Substances Act) as a derivative of 2-Phenylethylamine.[19]
Sweden: Following a suggestion by Sweden's public health agency that ephenidine be classified as a hazardous substance on June 2015, ephenidine became a scheduled substance as of August 2015.[20]
Switzerland: Ephenidine is a controlled substance specifically named under Verzeichnis E.[21]
Turkey: Ephenidine is a classed as drug and is illegal to possess, produce, supply, or import.[22]
United Kingdom: Ephenidine is illegal to produce, supply, or import in the U.K. under the Psychoactive Substance Act, which came into effect on May 26th, 2016.[23]
United States: Ephenidine could possibly be considered a positional isomer of SPA (lefetamine), which is a Schedule IV drug.[24] However, the isomer clauses within the legal text of the Schedules have rarely, if ever, been used for prosecution.
Wallach, J., Kang, H., Colestock, T., Morris, H., Bortolotto, Z. A., Collingridge, G. L., ... & Adejare, A. (2016). Pharmacological investigations of the dissociative ‘legal highs’ diphenidine, methoxphenidine and analogues. PLoS One, 11(6), e0157021. https://doi.org/10.1371/journal.pone.0157021
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
Wink, Carina S. D., et al. “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, John Wiley & Sons, Ltd, 3 Mar. 2014, https://onlinelibrary.wiley.com/doi/abs/10.1002/dta.1621.
“Toxicokinetics of Lefetamine and Derived Diphenylethylamine Designer Drugs-Contribution of Human Cytochrome P450 Isozymes to Their Main Phase I Metabolic Steps.” Toxicology Letters, Elsevier, 11 Aug. 2015, https://www.sciencedirect.com/science/article/pii/S0378427415300333.
Eiden, Céline, et al. “Ephenidine, Diphenidine, and Methoxphenidine Complications Reported to the French Addictovigilance Network.” Fundamental & Clinical Pharmacology, John Wiley & Sons, Ltd (10.1111), 23 July 2018, https://onlinelibrary.wiley.com/doi/abs/10.1111/fcp.12395.
↑Morris, H., Wallach, J. (August 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. doi:10.1002/dta.1620. ISSN1942-7611.
↑Van Hout, M. C., Hearne, E. (March 2015). ""Word of mouse": indigenous harm reduction and online consumerism of the synthetic compound methoxphenidine". Journal of Psychoactive Drugs. 47 (1): 30–41. doi:10.1080/02791072.2014.974002. ISSN0279-1072.
↑Wink, C. S. D., Meyer, G. M. J., Wissenbach, D. K., Jacobsen-Bauer, A., Meyer, M. R., Maurer, H. H. (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): 1038–1048. doi:10.1002/dta.1621. ISSN1942-7611.
↑Wink, C. S. D., Meyer, G. M. J., Meyer, M. R., Maurer, H. H. (4 November 2015). "Toxicokinetics of lefetamine and derived diphenylethylamine designer drugs-Contribution of human cytochrome P450 isozymes to their main phase I metabolic steps". Toxicology Letters. 238 (3): 39–44. doi:10.1016/j.toxlet.2015.08.012. ISSN1879-3169.
↑"Neue-psychoaktive-Stoffe-Gesetz (NpSG)" [New Psychoactive Substances Act (NpSG)] (PDF) (in Deutsch). Bundesamt für Justiz [Federal Office of Justice]. November 21, 2016. Retrieved August 14, 2020.
. PMID 27520396.