Abstract

Ephedra alkaloids in 47 dietary supplements were measured to examine variability within and between products as well as for comparison of actual constituents with label claims of manufactured products. Samples were analyzed for (-)-ephedrine, (+)-pseudoephedrine, (-)-methylephedrine, (+)-methylpseudoephedrine,(-)-norephedrine, and (+)-norpseudoephedrine without derivatization using gas chromatographic mass spectrometry (GC/MS). Samples were then screened for pharmaceutically derived chiral contaminants. The resulting data demonstrated that label claims matched total ephedra alkaloid content to within about 25% for most of the supplements, and no products purporting to be ephedrine-free contained any ephedra alkaloids. Furthermore, chiral analysis of these dietary supplements revealed only naturally occurring ephedra alkaloids. (-)-Ephedrine and (+)-pseudoephedrine accounted for > 95% of the alkaloid content in each of the ephedra-containing products. Examination of identical supplements originating from different lots revealed consistency in total alkaloid content between lots but large variations in specific individual alkaloid content.