|Summary sheet: 4F-EPH
|Routes of Administration
4-Fluoroethylphenidate (commonly known as 4F-EPH) is a novel synthetic stimulant of the phenidate chemical class that produces long-lasting euphoric and stimulating effects associated with potent monoamine reuptake inhibitors when administered. It is a closely related structural analog of the commonly prescribed ADHD drug methylphenidate (known by the brand-names Ritalin and Concerta) as well as a designer drug analog ethylphenidate. Based on its similarities to other memebers of this class, it is speculated to exert its activity as some form of double or triple monoamine reuptake inhibitor.
4F-EPH has little to no history of recreational use and has yet to be documented being sold on the streets. It was initially developed as a replacement and successor for compounds like ethylphenidate, which became illegal in the United Kingdom on April 2015, and later 4F-MPH. In 2016, it became made available for sale on the online gray market as a research chemical.
Due to its potent, long-lasting stimulant effect, likely habit-forming properties as well as unknown short and long-term toxicity profile, it is strongly recommended that one use proper harm reduction practices if choosing to use this substance.
4F-EPH, or 4-fluoroethylphenidate, is a synthetic molecule of the phenidate and substituted phenethylamine classes. It contains a phenethylamine core featuring a phenyl ring bound to an amino -NH2 group through an ethyl chain. It is structurally similar to amphetamine, featuring a substitution at Rα which is incorporated into a piperidine ring ending at the terminal amine of the phenethylamine chain. It contains an ethyl acetate bound to Rβ of its structure and is fluorinated at R4 of its phenyl ring.
4F-EPH is the 4-substituted flourine derivative of ethylphenidate, and is structurally different to methylphenidate by elongation of the carbon chain and the addition of a fluorine group. Ethyl- regards the side chain of two carbon atoms, phen- indicates the phenyl ring, id- is contracted from a piperidine ring, and -ate indicates the acetate group containing the oxygens. 4F-EPH is a chiral compound, presumably produced as a racemic mixture.
4F-EPH is believed to act as a higher efficiency dopamine reuptake inhibitor than the closely related methylphenidate, meaning that it effectively boosts the levels of dopamine neurotransmitters in the brain by binding to and partially blocking the transporter proteins that normally remove those monoamines from the synaptic cleft. This allows dopamine to accumulate within the certain focalized regions of the brain, resulting in stimulating and euphoric effects.
|This subjective effects section is a stub.
As such, it is still in progress and may contain incomplete or wrong information.
You can help by expanding or correcting it.
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 PsychonautWiki contributors. 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 ☠.
- Stimulation - 4F-EPH is considered to be mildly to moderately stimulating in a way that is quite unique for a dopaminergic stimulant and likely is the result of activity beyond dopamine and norepinephrine reuptake inhibition. Even in high doses it is much less stimulating and distinctively different than the closely related chemical 4F-MPH. The style of stimulation can be described as smooth, with a slight to moderate energetic push similar to, but drastically weaker than methamphetamine. It is much subtler and less forced than that of 4F-MPH, methylphenidate, and amphetamine.
- Dehydration - Relatively mild, provided one consumes an appropriate amount of water. Water should be sipped slowly at spaced intervals to prevent water intoxication.
- Appetite suppression - This effect is mild.
- Increased heart rate - 4F-EPH has a moderate effect on heart rate that is not concerning or uncomfortable at moderate doses.
- Increased blood pressure - A slight-moderate increase in blood pressure is seen with this compound, but only very excessive doses will usually raise it to problematic levels.
- Teeth grinding - This component can be considered to be less intense when compared with that of MDMA. It is very minimal at moderate doses and only excessive doses usually cause this effect. Even then it is rarely severe enough to reach an uncomfortable or damaging degree. Magnesium supplementation may reduce this.
- Pupil dilation - Pupil dilation is minimal at low-moderate doses, but can be pronounced during the offset of higher doses.
- Stamina enhancement - This component is much weaker than that of most other stimulants, such as methylphenidate and 4F-MPH.
- Vasoconstriction - This effect is much milder than that of most other dopaminergic stimulants at the peak, however it may rapidly become uncomfortable or even dangerous during the offset of very high doses or in individuals with circulatory problems. Blue or deep purple coloration or wrinkling of the skin of the extremities is a medical emergency if it isn't resolved quickly. Putting the hands and feet in a hot bath may help this effect, however fully submersing oneself in hot water is potentially dangerous.
- Nasal damage - 4F-EPH is notably less caustic than EPH (ethylphenidate), however it is still mildly to moderately caustic to the nasal cavities. It is recommended to perform a sterile saline nasal rinse 15 minutes after snorting this substance. Even with that precaution, intranasal use without significant breaks to allow the nasal cavities to repair themselves will likely still damage the nasal mucous membranes. It is unknown whether this results in permanent injury or simply acute damage.
- Increased libido - There is often a noticeable increase in libido at low-moderate doses, however this effect is much weaker than that experienced with 4F-MPH and methamphetamine. The style of sexual stimulation induced is an increase in the emotional enjoyment and sensations of sexual activity, but with minimal effect on or even a reduction in the pleasure of orgasm. This effect is less distracting and can be ignored more easily than that induced by many other dopaminergic stimulants.
- Decreased libido - Decreased libido inconsistently occurs at any dose, but high doses increase the likelihood and may be related to unproven, but subjectively theorized serotonergic activity.
- Orgasm suppression - Orgasm suppression usually only occurs at high doses and can be described as difficulty reaching an orgasm despite increased or normal libido. This is present primarily in males.
- Temporary erectile dysfunction - This is a common occurrence at moderate-high doses. Note that it is extremely unsafe for the heart to try to counteract this by combining erectile dysfunction drugs with stimulants.
- Physical euphoria - A slight to moderate sense of pleasant well-being and physical comfort is often present at a low level throughout the peak and is strongest at moderate doses. This effect is similar to, but much weaker than that induced by methamphetamine and MDMA. It reduces or disappears when used in high doses or when repeatedly redosed.
- Spontaneous physical sensations - Highly euphoric, mild-distinct and all-encompassing sharp tingling sensations that fade rapidly into soft sensations before disappearing frequently occur during the initial "rush" of moderate-high doses. This is particularly powerful when vaporized or injected intravenously. It is comparable to that experienced during and shortly after orgasm, although a lot milder. This effect rarely if ever occurs when consumed orally, but may occur when administered via intranasal or sublingual routes, though it is usually to a lesser degree. The rush produced by 4F-EPH may last up to 15 minutes, however it most commonly lasts around 5 minutes. It diminishes in strength rapidly and eventually disappears when redosed repetitively.
- Perception of bodily lightness - A mild and pleasant feeling of lightness/floating as well as effortless movement in the entire body frequently occurs during the rush and often persists into the peak for some time. This may occur via any route. It is most common at moderate-high doses and tends to reduce or disappear at excessive doses.
- Thought acceleration - The thought acceleration induced by 4F-EPH is mild to moderate and is not usually strong enough to induce confusion. It tends towards semantic, emotional, social, and abstract thought patterns.
- Analysis enhancement - 4F-EPH has the capability of enhancing analytical ability, but only at low doses and very inconsistently. Moderate to high doses do not usually enhance logical analytical abilities and tend instead toward semantic and emotional thought patterns.
- Wakefulness - 4F-EPH is relatively weak in wakefulness-promoting abilities when compared to methylphenidate, amphetamine, and most other dopaminergic stimulants.
- Focus enhancement - 4F-EPH does not have much potential for use a "functional" stimulant to complete mundane tasks, as the focus enhancement induced by 4F-EPH tends to be inconsistent and mild in strength. It is usually only at low doses that focus enhancement may occur. Moderate and high doses tend to decrease the ability to focus on mundane tasks due to the pleasant recreational effects of physical and empathetic euphoria and abstract thought patterns. 4F-EPH is, however, effective for creative and abstract tasks such as art and fiction writing.
- Motivation enhancement - This component is mild and usually present only at low doses. Moderate and high doses tend to instead strongly promote socialization and recreational activities such as gaming and watching movies.
- Euphoria - The cognitive euphoria of 4F-EPH is subtle, relaxing, and often very pleasant. It tends to promote feelings of physical and mental well-being, as well as creative thoughts. Very excessive doses may instead result in dysphoria.
- Increased music appreciation - 4F-EPH noticeably increases the enjoyment of music.
- Cognitive fatigue
- Empathy, affection, and sociability enhancement - 4F-EPH may result in mild empathetic and affectionate feelings, particularly at lower doses. This substance commonly results in an intense drive to socialize with others that strengthens with increasing dosage.
- The effects which occur during the offset of a stimulant experience generally feel negative and uncomfortable in comparison to the effects which occurred during its peak. This is often referred to as a "comedown" and occurs because of neurotransmitter depletion. Its effects commonly include:
Anecdotal reports which describe the effects of this compound within our experience index include:
Toxicity and harm potential
This toxicity and harm potential section is a stub.
As a result, it may contain incomplete or even dangerously wrong information! You can help by expanding upon or correcting it.
The toxicity and long-term health effects of recreational 4F-EPH use do not seem to have been studied in any scientific context and the exact toxic dosage is unknown. This is because 4F-EPH is a research chemical with very little history of human usage. Anecdotal evidence from people who have tried 4F-EPH suggests that there are no negative health effects attributed to simply trying the drug by itself at low to moderate doses and using it very sparingly (but nothing can be completely guaranteed).
It is strongly recommended that one use harm reduction practices when using this drug.
Tolerance and addiction potential
As with other stimulants, the chronic use of 4F-EPH 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 a person suddenly stops their usage.
Tolerance to many of the effects of 4F-EPH 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). 4F-EPH presents cross-tolerance with all dopaminergic stimulants, meaning that after the consumption of 4F-EPH all stimulants will have a reduced effect.
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.
- 25x-NBOMe & 25x-NBOH - 25x compounds are highly stimulating and physically straining. Combinations with 4F-EPH should be strictly avoided due to the risk of excessive stimulation and heart strain. This can result in increased blood pressure, vasoconstriction, panic attacks, thought loops, seizures, and heart failure in extreme cases.
- Alcohol - Combining alcohol with stimulants can be dangerous due to the risk of accidental over-intoxication. Stimulants mask alcohol's depressant effects, which is what most people use to assess their degree of intoxication. Once the stimulant wears off, the depressant effects will be left unopposed, which can result in blackouts and severe respiratory depression. If mixing, the user should strictly limit themselves to only drinking a certain amount of alcohol per hour.
- DXM - Combinations with DXM should be avoided due to its inhibiting effects on serotonin and norepinephrine reuptake. There is an increased risk of panic attacks and hypertensive crisis, or serotonin syndrome with serotonin releasers (MDMA, methylone, mephedrone, etc.). Monitor blood pressure carefully and avoid strenuous physical activity.
- MDMA - Any neurotoxic effects of MDMA are likely to be increased when other stimulants are present. There is also a risk of excessive blood pressure and heart strain (cardiotoxicity).
- MXE - Some reports suggest combinations with MXE may dangerously increase blood pressure and increase the risk of mania and psychosis.
- Dissociatives - Both classes carry a risk of delusions, mania and psychosis, and these risk may be multiplied when combined.
- Stimulants - 4F-EPH may be dangerous to combine with other stimulants like cocaine as they can increase one's heart rate and blood pressure to dangerous levels.
- Tramadol - Tramadol is known to lower the seizure threshold and combinations with stimulants may further increase this risk.
- MAOIs - This combination may increase the amount of neurotransmitters such as dopamine to dangerous or even fatal levels. Examples include syrian rue, banisteriopsis caapi, and some antidepressants.
This legality section is a stub.
As such, it may contain incomplete or wrong information. You can help by expanding it.
- Germany: 4-Fluoroethylphenidate is controlled under the NpSG (New Psychoactive Substances Act) as of November 26, 2016. 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.
- Switzerland: 4F-EPH is a controlled substance specifically named under Verzeichnis E.
- Turkey: 4F-EPH is a classed as drug and is illegal to possess, produce, supply, or import.
- United Kingdom: 4-Fluoroethylphenidate is a class B drug in the UK as of May 31st 2017, making it illegal to possess, produce or supply. 
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- Misra, M., Shi, Q., Ye, X., Gruszecka-Kowalik, E., Bu, W., Liu, Z., Schweri, M. M., Deutsch, H. M., Venanzi, C. A. (15 October 2010). "Quantitative structure-activity relationship studies of threo-methylphenidate analogs". Bioorganic & Medicinal Chemistry. 18 (20): 7221–7238. doi:10.1016/j.bmc.2010.08.034. ISSN 1464-3391.
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- Talaie, H.; Panahandeh, R.; Fayaznouri, M. R.; Asadi, Z.; Abdollahi, M. (2009). "Dose-independent occurrence of seizure with tramadol". Journal of Medical Toxicology. 5 (2): 63–67. doi:10.1007/BF03161089. eISSN 1937-6995. ISSN 1556-9039. OCLC 163567183.
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- "Anlage NpSG" (in German). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 23, 2019.
- "Gesetz zur Bekämpfung der Verbreitung neuer psychoaktiver Stoffe" (PDF) (in German). Bundesanzeiger Verlag. Retrieved December 23, 2019.
- "§ 4 NpSG" (in German). Bundesministerium der Justiz und für Verbraucherschutz. Retrieved December 23, 2019.
- "Verordnung des EDI über die Verzeichnisse der Betäubungsmittel, psychotropen Stoffe, Vorläuferstoffe und Hilfschemikalien" (in German). Bundeskanzlei [Federal Chancellery of Switzerland]. Retrieved January 1, 2020.
- Cumhurbaşkanı Kararı CK Karar Sayısı : 1335 | https://resmigazete.gov.tr/eskiler/2019/07/20190720-19.pdf
- The Misuse of Drugs Act 1971 (Amendment) Order 2017