4F-MPH (4-Fluoromethylphenidate, 4-FMPH) is a novel synthetic stimulant of the substituted phenethylamine and piperidine classes that produces long-lasting euphoriant, and stimulating effects associated with monoamine reuptake inhibitors when adminstered. 4F-MPH (4-Fluoromethylphenidate, 4-FMPH) is a closely related structural analog of the commonly prescribed ADHD drug Methylphenidate (known by the brand-names Ritalin and Focalin).
The two substances are believed to have very similar pharmacological mechanisms but have been reported to display distinctive subjective effects, with 4F-MPH (4-Fluoromethylphenidate, 4-FMPH) being considered significantly more euphoric and recreational. Anecdotal reports indicate that 4F-MPH is considerably more potent with fewer uncomfortable side effects such as anxiety, muscle spasms and compulsive redosing. This perhaps owes to the fact that it has been shown to act as a higher efficiency dopamine reuptake inhibitor than the parent compound Methylphenidate.
4F-MPH has an extremely short history of recreational use and has yet to be documented being sold on the streets. It was initially developed as a replacement for ethylphenidate which became illegal in the United Kingdom on April 2015 following a temporary blanket ban. Shortly after, it recently became made available for sale on the online gray market as a research chemical for global distribution.
Due to its potent, long-lasting stimulant effect, likely habit-forming properties as well as unknown toxicity profile, it is strongly recommended that one use proper harm reduction practices if choosing to use this substance.