4-FMA (4-Fluoromethamphetamine) Powder

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4-Fluoromethamphetamine (4-FMA) is a lesser-known novel stimulant-entactogen substance belonging to the amphetamine class. It is chemically related to both 4-FA and methamphetamine. Although little is known about its pharmacology, it is believed to produce its effects by increasing levels of dopamine, norepinephrine, and serotonin in the brain.

Market History

4-FMA was first detected in Japan as a legal high in 2006. It has since been sold online as a research chemical alongside other fluorinated amphetamines, including 2-fluoroamphetamine (2-FA), 3-fluoroamphetamine (3-FA), and 4-fluoroamphetamine (4-FA). Following the prohibition of 4-FA in the Netherlands in 2017, 4-FMA gained popularity as a legal substitute due to their similar names and effects. By 2018, an increasing number of analyzed 4-FA samples contained 4-FMA, while the availability of actual 4-FA sharply declined.

User Reports

User reports describe the effects of 4-FMA as exhibiting characteristics of both traditional stimulants, such as amphetamine, and entactogens, like MDMA. Its effects are often described as subjectively lying between those of 4-FA and 2-FMA.

Chemistry

4-Fluoromethamphetamine (4-FMA) is a synthetic molecule within the substituted amphetamine family. Molecules in this class contain a phenethylamine core, characterized by a phenyl ring connected to an amino (NH2) group through an ethyl chain, with an additional methyl substitution at Rα. The term "amphetamine" is derived from alpha-methylphenethylamine. 4-FMA contains a fluorine atom at the R4 position of its phenyl ring, making it a fluorinated analogue of methamphetamine.

Pharmacology

Similar to its structural analog 4-FA, 4-Fluoromethamphetamine is thought to act as a releasing agent and reuptake inhibitor for dopamine, serotonin, and norepinephrine. At lower doses, it produces stimulating amphetamine-like effects, while at dosages above 125 mg, it elicits more euphoric, entactogenic effects akin to MDA. Research indicates some similarities between the serotonin release of 4-FMA and other popular empathogens, such as MDA, 4-Methylmethcathinone, and 4-fluoroamphetamine.

The mechanism of action for 4-FMA involves boosting the levels of norepinephrine, dopamine, and serotonin in the brain by binding to and partially blocking the transporter proteins that typically clear these monoamines from the synaptic cleft. This accumulation of neurotransmitters in various brain regions, including reward pathways, results in stimulating, euphoric, and entactogenic effects.

Additionally, 4-FMA is a CYP450 inhibitor, which reduces the metabolism of methamphetamine, thereby increasing its potency, duration, and systemic toxicity while also reducing its cellular toxicity.

Subjective Effects

At low doses, 4-FMA has been reported to be a lackluster nootropic for general productivity. However, such usage is strongly discouraged due to the increased risks of neurotoxicity and other dangerous side effects. This caution is based on studies indicating that 4-FMA is similar to MDA and belongs to the entactogen class. Frequent use of any entactogen is considered dangerous, and taking "microdoses" below the minimum dose required to experience a "roll" is seen as unwise.

At higher dosages, 4-FMA is known to become dysfunctional and recreational, characterized by a scattering quality of its euphoria and stimulation. Similar to MDA, MDMA, and 4-FA, 4-FMA can produce distinct pleasurable tactile "roll"-like sensations, typically linked to serotonin-releasing properties. However, some reports suggest that 4-FMA tends to come with more side effects and bodily strain than other fluorinated amphetamines, which may explain its lack of popularity and availability.

4-FMA (4-Fluoromethamphetamine) Powder is for research use only and not intended for human consumption!

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4-FMA (4-Fluoromethamphetamine) Powder stock last updated at: April 2025