β-Methylphenethylamine (BMPEA)
β-Methylphenethylamine (BMPEA) is a positional isomer of amphetamine that gained attention after being found as an undeclared adulterant in some dietary supplements marketed as containing Acacia rigidula. It is a stimulant with limited human data and unknown long-term safety.
01 Overview
BMPEA differs from amphetamine only in the position of the methyl group, moved from the alpha to the beta carbon. This makes it a close structural relative with sympathomimetic stimulant activity, though it is generally considered less potent orally than amphetamine.
It drew regulatory and media attention when analytical studies found it in supplements sold for weight loss and athletic performance, where consumers were exposed to an untested amphetamine isomer without knowing it. Direct human pharmacology is sparse, and its cardiovascular safety at the doses present in such products is unestablished.
02 Mechanism
Sympathomimetic phenethylamine acting as a monoamine releaser, structurally a beta-methyl isomer of amphetamine.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Light | 15–40 mg | Insufflated | Unstudied. |
| Common | 20–60 mg | Oral | Anecdotal only; also encountered as an unlabelled supplement adulterant at variable amounts. |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| StimulationIncreased energy and alertness. | Anecdotal | ||
| Appetite suppressionReduced hunger; the reason it appeared in weight-loss products. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Tachycardia and hypertensionRaised heart rate and blood pressure; of particular concern given undisclosed presence in supplements. | Severe | Common | Unconfirmed | |
| InsomniaSleep disruption after dosing. | Moderate | Common | Anecdotal | |
| AnxietyRestlessness and anxiety. | Moderate | Common | Anecdotal |