Research chemicalStimulantResearch chemical
4-FMP (4-Fluorophenmetrazine)
Also known as 4-FMP · 4-FPM · 4-Fluorophenmetrazine · para-Fluorophenmetrazine
4-FMP (4-fluorophenmetrazine, 4-FPM) is a fluorinated phenmetrazine analogue and research-chemical stimulant. It is reported as a functional, balanced stimulant, but human pharmacological data is minimal.
01 Overview
4-FMP is the para-fluorinated analogue of phenmetrazine, one of several positional fluorophenmetrazine research chemicals to appear on the market alongside 3-FPM. It is described by users as a moderate, relatively balanced stimulant.
Dedicated human data is essentially absent, and its pharmacology is inferred from phenmetrazine and its 3-substituted isomer. Cardiovascular and long-term risks remain poorly defined.
02 Mechanism
Presumed norepinephrine-dopamine releasing agent analogous to phenmetrazine, promoting catecholamine release.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Light | 20–40 mg | Oral | Anecdotal light range. |
| Common | 40–80 mg | Oral | Anecdotal functional range; poorly characterised. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Functional stimulationEnergy, focus and wakefulness reported as relatively balanced. | moderate | Anecdotal | |
| Appetite suppressionReduced hunger consistent with its phenmetrazine lineage. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Insomnia and comedownSleep disruption followed by fatigue and low mood. | Moderate | Common | Anecdotal | |
| Compulsive redosingRedosing common as effects taper, increasing total exposure. | Moderate | Common | Anecdotal | |
| Cardiovascular strainTachycardia and hypertension presumed by analogy to phenmetrazine; not documented in humans. | Severe | Unknown | Unconfirmed |
06 Legal status
UK
Psychoactive Substances Act 2016
Production and supply prohibited. · as of Jan 2026
United States
Analogue exposure possible
Not explicitly scheduled; may fall under analogue provisions. · as of Jan 2026
07 References
Fluorophenmetrazine analogues and stimulant pharmacologyPubMed
New psychoactive substances overviewEUDA (European Union Drugs Agency)
08 Discussion0 comments
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This page is reference information, not medical advice. Doses and protocols are documented as they appear in the clinical literature and in practice — describing them is not a recommendation to use them. Countermeasures listed here are not a substitute for a physician. Legal status varies by jurisdiction and changes.