Drug use histories were collected from 100 subjects recruited from the "dance scene" in and around Glasgow. In addition, each subject donated a hair sample that was analyzed by gas chromatography/mass spectrometry (GC/MS) for amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), and 3,4-methylenedioxyethylamphetamine (MDEA). The hair samples were analyzed in two 6 cm segments or in full, ranging from 1.5 to 12 cm, depending on the length of the hair. Approximately 10 mg of hair was ground to a fine powder before treatment with B-glucuronidase/aryl sulfatase. A solid-phase extraction procedure was conducted, followed by derivatization with pentafluoropropionic anhydride (PFPA). All extracts were analyzed by GC/MS. Of the 139 segments analyzed, 77 (52.5 percent) were positive for at least one of the five amphetamines. The drug concentrations found in the hair were compared with the self-reported drug histories. A concordance of greater than 50 percent was found between the self-report data and levels detected in hair; however, no correlation was found between the reported number of "ecstasy" tablets consumed and the drug levels detected in hair. An increase in the average drug levels measured was observed from low to high use (number of "ecstasy" tablets per month). A large number of false negatives and a low number of false positives were observed. 7 tables, 4 figures, and 34 references