It has recently been reported that purity of illicit tablets of ecstasy (MDMA) is now high. Our objective was to confirm whether hair of drug users, who request only ecstasy from their supplier, contains MDMA in the absence of other drugs. GC-MS analysis of scalp hair segments disclosed the presence of MDMA in 19 of 21 subjects and amphetamine/methamphetamine in eight subjects. Surprisingly, seven subjects had hair levels of the MDMA metabolite, MDA, equal to or greater than those of MDMA, suggesting use of MDA in addition to that of MDMA. These amphetamine derivatives might be included by clandestine laboratories to enhance effects of the drug cocktail or because of a perception that MDA synthesis might be simpler than that of MDMA. Drug users and investigators examining possible brain neurotoxic effects of MDMA need to consider that "ecstasy" tablets can contain MDA and methamphetamine despite no demand for the drugs.