Research chemicalEntactogenSubstituted amphetamineSerotonin releaser

4-MMA

Also known as 4-methylmethamphetamine · Methyl-4-MA

Written by enwyReviewed 5 Aug 20261 sources0 comments

4-MMA (4-methylmethamphetamine) is a ring-methylated methamphetamine with a strongly serotonergic, entactogen-like profile. It is notably more dangerous than its recreational reputation suggests, having been implicated in fatalities linked to hyperthermia and serotonin toxicity. Human data are limited to case reports.

01 Overview

4-MMA is closely related to the serotonergic amphetamine 4-MTA and to PMMA in its toxic profile: it releases serotonin heavily while providing weak, delayed reward, encouraging redosing. This combination has driven overdose deaths.

Reliable human pharmacology is absent; the main record is toxicological. It carries pronounced serotonergic neurotoxicity, hyperthermia, and serotonin-syndrome risk. It is controlled or analog-covered in many jurisdictions.

02 Mechanism

Potent serotonin-releasing agent (with weaker dopamine release) at monoamine transporters, and a partial monoamine oxidase inhibitor, producing strong serotonergic effects and toxicity.

03 Dosing

Tier	Dose	Route	Notes
Light	30–60 mg	Oral	Delayed onset invites dangerous redosing; caution
Common	60–100 mg	Oral	Narrow margin to toxicity

04 Effects

Effect	Magnitude	Evidence
Serotonergic entactogenesisEmotional effects that come on slowly, encouraging redosing.	Moderate, delayed	Anecdotal
Mild stimulationWeaker and less rewarding than methamphetamine despite the name.	Mild	Anecdotal

05 Side effects

Effect	Severity	Frequency	Evidence
HyperthermiaSevere overheating, a leading feature of reported 4-MMA fatalities.	Life-threatening	Uncommon but implicated in deaths	Observational
Serotonin syndromeIts partial MAOI action raises serotonin-toxicity risk even without other drugs.	Life-threatening	Elevated due to MAOI activity	Observational
Serotonergic neurotoxicityStrong serotonin release predicts axonal neurotoxicity as with related compounds.	Severe	Dose-dependent, uncertain in humans	Preclinical

06 Legal status

United States

Possible Analog Act coverage

as of Jan 2026

United Kingdom

Class B (amphetamine class)

as of Jan 2026

07 References

Fatal intoxications involving 4-methylmethamphetamine (4-MMA)Forensic Science International

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.