PMA (para-Methoxyamphetamine)
PMA (para-methoxyamphetamine) is a highly dangerous amphetamine notorious for causing fatal overdoses. It has a slow, delayed onset that leads users to redose thinking it is weak or fake MDMA, then produces severe, sometimes lethal hyperthermia and serotonin toxicity. Numerous deaths have been documented.
01 Overview
PMA is a para-methoxy substituted amphetamine that acts strongly on the serotonin system and is a potent monoamine oxidase inhibitor. It has repeatedly appeared in the illicit market misrepresented as MDMA or pressed into ecstasy tablets, where it has caused clusters of deaths.
The central danger is its delayed onset: effects can take well over an hour to appear, far longer than MDMA. Users who feel nothing take a second or third dose, then all of it takes hold at once. The result is dangerously high body temperature, agitation, seizures and cardiovascular collapse. Because PMA also inhibits MAO, serotonin cannot be cleared normally, and combinations with other serotonergic drugs are especially lethal. This delayed-onset redosing trap is the mechanism behind most PMA fatalities and should be stated plainly: PMA kills people who mistake it for a weak dose.
02 Mechanism
Potent serotonin releaser and reuptake inhibitor that also inhibits monoamine oxidase, producing serotonin accumulation, hyperthermia and cardiovascular toxicity. Onset is markedly delayed.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Threshold | 20–50 mg | Oral | There is no safe dose. Delayed onset makes redosing extremely dangerous; toxicity and death have occurred at doses users considered small. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Delayed, MDMA-like effectsSlow-building stimulation and warmth that lead users to redose prematurely. | onset often >1 hour | Observational | |
| StimulationIncreased energy and arousal once effects appear. | Observational |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Fatal hyperthermiaSevere elevation of body temperature is the leading cause of PMA death, driven by the delayed-onset redosing pattern. | Life-threatening | Common at active/overdose levels | Observational | |
| Serotonin syndromeAgitation, rigidity, hyperthermia and seizures, especially with serotonergic combinations. | Life-threatening | Common | Observational | |
| Cardiac arrhythmia and collapseSevere tachycardia, arrhythmia and cardiovascular collapse. | Life-threatening | Common | Observational |