We report here an in vitro pharmacologic profile for MDMA (3,4-methylenedioxymethamphetamine) at various brain recognition sites. The rank order of affinities of MDMA at various brain receptors and uptake sites are as follows: 5-HT uptake greater than alpha 2-adrenoceptors = 5-HT2 serotonin = M-1 muscarinic = H-1 histamine greater than norepinephrine uptake = M-2 muscarinic = alpha 1-adrenoceptors = beta-adrenoceptors greater than or equal to dopamine uptake = 5-HT1 serotonin much greater than D-2 dopamine greater than D-1 dopamine. MDMA exhibited negligible affinities (greater than 500 microM) at opioid (mu, delta and kappa), central-type benzodiazepine, and corticotropin-releasing factor receptors, and at choline uptake sites and calcium channels.