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4f-MPH
4f-MPH belongs to the piperidine chemical class and is the 4-fluoro derivative of methylphenidate1. It had appeared on the recreational market by November 2015.2 It produces long-lasting increases in energy and alertness and is potent at low doses. Reports differ on its recreational effects, with some describing little euphoria and others describing greater euphoria than methylphenidate. It is considered likely to be habit-forming.
Dosage & Duration
Dosage
Doses are population estimates that vary widely between individuals.
Threshold5 mg
Light5-10 mg
Moderate10-15 mg
Strong15-20 mg
Heavy20+ mg
Duration
Onset30-60 minutes
Peak2-4 hours
Offset1-2 hours
After Effects5-10 hours
Total4-8 hours
Subjective Effects
Subjective Effects not written up yet
Pharmacology
Pharmacodynamics
4F-MPH inhibits dopamine and norepinephrine reuptake3, reducing their clearance by transporters and increasing their availability between nerve cells. Pharmacological testing indicates that this activity is substantially stronger in the (±)-threo isomer than in the (±)-erythro isomer.3 In rat brain synaptosome uptake assays, both racemates showed little activity at the serotonin transporter.3
Pharmacokinetics
Absorption & half-lifenot documented yetMetabolitesnone documented yet
Interactions
Interactions not written up yet
An unlisted combination is an unknown one, not a safe one. Check a dedicated combination chart before mixing.
Tolerance
Tolerance timelines are rules of thumb, not exact schedules, and vary widely between individuals and use patterns.
With consecutive use over extended periods, acute tolerance to 4F-MPH develops gradually, increasing the dose required to produce the same effects. Tolerance is reported to develop faster than with methylphenidate, although it is also described as lacking significant tolerance; no timeframe for full tolerance is specified.
Harm Potential
Addiction & Dependence
Psychological
High4F-MPH has abuse potential on par with amphetamine or MDMA due to its euphoric effects and action upon dopamine transporters. Some users have become addicted to this substance, and compulsive redosing is reported, particularly at high doses or with non-oral routes of administration.
Toxicity
Acute cardiovascular effects including abnormal heartbeat and vasoconstriction occur during use; excessive stimulation may result in dangerous increases in blood pressure and heart strain, particularly at higher doses or in combination with other stimulants.
Psychosis Risk
Risk of delusions, mania, and psychosis has been noted, particularly when combined with dissociatives. The substance may carry inherent psychosis risk at higher doses.
Seizure Risk
Seizures have been mentioned as a potential risk in extreme cases, particularly in combination with certain other substances.
History & Culture
4F-MPH was investigated alongside other analogues of (±)-threo-methylphenidate as a potential therapeutic for cocaine addiction.3…
Legality
By Country
Illegal4
GermanyIllegal (analog/blanket ban)4F-MPH falls within the generic structural definition for compounds derived from 2-phenethylamine in Anlage 1 Nr. 1 of the Neue-psychoaktive-Stoffe-Gesetz (NpSG). Section 3 prohibits trade, placing on the market, manufacture, import, export, transit, acquisition, possession, and administration to another person, subject to exceptions for recognized commercial, industrial, scientific, and specified official uses. Under section 4(1), trade, placing on the market, or administration to another person, as well as manufacture or import for the purpose of placing it on the market, is punishable by imprisonment for up to three years or a fine; simple acquisition or possession is not enumerated as a standalone offense in that provision. The NpSG excludes substances controlled under the Betäubungsmittelgesetz and qualifying medicinal products, veterinary medicinal products, and specified medical devices.
SwitzerlandIllegalVerordnung des EDI vom 30. Mai 2011 über die Verzeichnisse der Betäubungsmittel, psychotropen Stoffe, Vorläuferstoffe und Hilfschemikalien (Betäubungsmittelverzeichnisverordnung, BetmVV-EDI), Anhang 6, Verzeichnis e192021
4F-MPH is expressly listed as 4-Fluormethylphenidat, 4F-MPH, and Methyl-2-(4-fluorphenyl)-2-(piperidin-2-yl)acetat in item 196 of Annex 6, Verzeichnis e. Under BetmKV Article 3(2)(e), Verzeichnis e materials and products are subject to the control measures applicable to Verzeichnis a narcotics, and BetmG Article 7 requires authorization from the Federal Department of Home Affairs for their cultivation, manufacture, import, export, storage, use, or placing on the market. BetmG Article 20(1)(c) makes those acts without authorization punishable by up to three years' imprisonment or a monetary penalty.
TurkeyIllegal19/7/2019 tarihli ve 1335 sayılı Cumhurbaşkanı Kararı eki Liste; 2313 sayılı Uyuşturucu Maddelerin Murakabesi Hakkında Kanun, Madde 19; 5237 sayılı Türk Ceza Kanunu, Maddeler 188 ve 19191011
4-Fluoromethylphenidate (4F-MPH) is prohibited in Turkey. The annex to Presidential Decision No. 1335 of 19 July 2019 expressly lists 4-fluoromethylphenidate (4F-MPH) as methyl 2-(4-fluorophenyl)-2-(2-piperidyl)acetate and subjects it to Law No. 2313 under article 19; the decision was published in Resmî Gazete No. 30837 on 20 July 2019 and states no separate commencement clause. Turkish Penal Code article 188 prescribes twenty to thirty years' imprisonment and a judicial fine of 2,000 to 20,000 days for unauthorized manufacture, import, or export, and at least ten years' imprisonment and a judicial fine of 1,000 to 20,000 days for unauthorized domestic sale, offering for sale, supply, dispatch, transport, storage, purchase, acceptance, or possession. Article 191 prescribes two to five years' imprisonment for purchasing, accepting, or possessing the substance for personal use, or using it.
United KingdomIllegal4-Fluoromethylphenidate has been expressly listed as a Class B drug in Schedule 2 Part II of the Misuse of Drugs Act 1971 since 31 May 2017. The Act makes its production, supply, and possession unlawful, subject to regulations under section 7 and to the applicable offence provisions and defences.
Controlled / restricted1
United StatesRestrictedAlabama Administrative Code rule 420-7-2-A, Appendix Controlled Substances List, Schedule I(f)22232425262728293031
In Alabama, 4-Fluoromethyl-phenidate, also named 4-FTMP, is listed in Schedule I(f), item 297, of Alabama Administrative Code rule 420-7-2-A, with state control recorded from March 18, 2014. Schedule I(f) also covers the listed substance's salts, isomers, and salts of isomers when those forms can exist, unless specifically excepted. The DEA controlled-substances list dated August 27, 2026 does not name 4-Fluoromethylphenidate, 4F-MPH, or 4-FTMP, but an unlisted substance may still be regulated federally as a controlled-substance analogue when 21 U.S.C. §§ 802(32) and 813 apply.
Legal / decriminalized1
ItalyDecriminalized4F-MPH is expressly listed in Tabella I as methyl (4-fluorophenyl)(piperidin-2-yl)acetate and 4-fluoromethylphenidate, effective 2 November 2021. Under article 73 of D.P.R. 9 ottobre 1990, n. 309, unauthorized production and sale are criminal offences, as are unauthorized import, export, purchase, and possession when the substance is intended for use that is not exclusively personal. Under article 75, illicit import, export, purchase, receipt, or possession for personal use is an administrative offence rather than a criminal offence. Activities authorized under article 17 are outside article 73's unauthorized-conduct offences.
References
Citations
Further Reading
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