Ephedrine-type alkaloid content of nutritional supplements containing Ephedra sinica (Ma-huang) as determined by high performance liquid chromatography.

Nutritional supplements containing Ephedra sinica (ma-huang), a botanical source of ephedrine-type alkaloids, have been linked to numerous episodes of ephedrine (EPH) toxicity. With passage of the 1994 Dietary Supplement Health and Education Act, nutritional supplements are no longer subject to the same FDA preapproval requirements as food additives, prescription, or nonprescription medications. As a consequence, EPH content is not a label requirement for Ephedra-containing supplements. Less stringent labeling requirements, therefore, may contribute to toxicity associated with these products. A validated HPLC method for the determination of ephedrine-type alkaloids, commonly found in Ephedra supplements, is presented. Nine commercially available supplements exhibited considerable variability in alkaloid content (EPH range: 1.08-13.54 mg). Only three products listed EPH content on the label while one exhibited lot to lot variations in EPH of 137%.