4-Methylamphetamine (4-MA)
4-Methylamphetamine (4-MA) is a ring-methylated amphetamine that acts as a strongly serotonergic monoamine releaser. Several deaths have been reported in Europe, often when it was sold as or mixed with amphetamine, and its serotonergic profile makes overdose particularly dangerous.
01 Overview
4-MA carries a methyl group on the para position of the amphetamine ring, shifting its activity toward serotonin release relative to amphetamine while retaining noradrenaline and dopamine release. This gives it a mixed stimulant-serotonergic profile that is more toxic than its stimulant effects alone would suggest.
European drug-monitoring bodies documented a cluster of deaths associated with 4-MA, frequently when it contaminated or was substituted for amphetamine so users did not know what they had taken. This should be stated plainly: 4-MA has caused fatal poisonings, with hyperthermia and serotonin toxicity implicated, and the risk is amplified when it is combined with other serotonergic drugs.
02 Mechanism
Monoamine releaser with strong serotonergic activity alongside noradrenaline and dopamine release; the serotonergic component drives its disproportionate toxicity.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Threshold | 20–50 mg | Oral | No safe dose; deaths have occurred, often when sold as amphetamine. Serotonergic toxicity makes overdose especially dangerous. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| StimulationAmphetamine-like stimulation reported. | Observational | ||
| Empathogenic mood changeSome serotonergic, entactogen-like mood effects. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Fatal hyperthermia and serotonin toxicityDeaths reported with features of hyperthermia and serotonin toxicity, especially when unknowingly consumed as amphetamine. | Life-threatening | Documented in fatal cases | Observational | |
| Cardiovascular strainTachycardia and hypertension. | Severe | Common | Observational | |
| Anxiety and agitationRestlessness and agitation. | Moderate | Common | Anecdotal |