Methylone: general

Methylone is a synthetic cathinone, a stimulant and psychoactive drug closely related in chemistry and effects to MDMA — it's sometimes described as MDMA's beta-keto cousin, and users often reach for it as a substitute [1][2][3][4]. It has no medical use [3], and it strongly increases dopamine release [2]. It's one of the most widely encountered synthetic cathinones sold as an MDMA stand-in, precisely because the effects feel similar to users [4].

The most important thing to know: solid human pharmacology data on methylone is limited [5]. That's not a technicality.

If you're using it, that gap should change your behaviour — start with less than you think you need, don't use alone, and don't combine it with other serotonergic or stimulant substances.

Methylone is Schedule I under U.S. federal law [6].

Two chemistry notes worth having straight: methylone is the beta-keto analogue of MDMA [3][5], structurally and pharmacologically in the same family as amphetamine, cathinone, and MDMA itself [6]. Despite that resemblance, it isn't the same molecule.

References

1. 3,4-Methylenedioxymethcathinone (Methylone) [“Bath salt,” bk-MDMA, MDMC, MDMCAT, “Explosion,” “Ease,” “Molly”] — U.S. Drug Enforcement Administration (DEA)
2. NCATS Inxight Drugs — MDMC — National Center for Advancing Translational Sciences (NCATS)
3. Methylone - Expert Committee on Drug Dependence Information Repository — World Health Organization (WHO)
4. Pharmacological effects of methylone and MDMA in humans — Frontiers in Pharmacology
5. Abuse Potential and Human Pharmacology of Methylone — U.S. National Library of Medicine (ClinicalTrials.gov)
6. Federal Register, Volume 78 Issue 71 (Friday, April 12, 2013) — U.S. Government Publishing Office (Federal Register)