3,4-Methylenedioxymethamphetamine is a ring-substituted amphetamine derivative, structurally related to the hallucinogen mescaline, with entactogenic, neurotoxic, and motor-stimulatory activities. 3,4-methylenedioxymethamphetamine (MDMA) produces an acute, rapid enhancement in both the release of serotonin from and the inhibition of serotonin reuptake by serotonergic nerve endings in the brain.