RESUMEN
Consumption of Ephedra alkaloids is prohibited in-competition by the World Anti-Doping Agency (WADA). In Taiwan, colds are often treated with Chinese herbal formulae containing Herba Ephedrae. We screened products sold in Taiwan and preliminarily assessed their relationships with WADA threshold violations. Fifty-six concentrated powder products, including 19 Chinese herbal formulae that contained Herba Ephedrae, were collected. The content of Ephedra alkaloids, namely ephedrine (E), methylephedrine (ME), norpseudoephedrine (NPE; cathine), pseudoephedrine (PE), and norephedrine (NE; phenylpropanolamine), was determined using a validated high-performance liquid chromatography method. The results revealed that the phenotypic indicators of the collected products, E/PE and E/total ratios, were 1.52-4.70 and 0.49-0.72, respectively, indicating that the Herba Ephedrae species in these products was probably E. sinica or E. equisetina, but not E. intermedia. The contents of E, ME, NPE, PE, and NE and the total alkaloid contents in the daily doses of the products were 0.45-34.97, 0.05-4.87, 0.04-3.61, 0.15-12.09, and 0.01-2.00 mg and 0.68-53.64 mg, respectively. The alkaloid contents followed a relatively consistent order (E > PE > ME ≈ NPE > NE), even for products from different manufacturers. We calculated that single doses of 50.0% and 3.6% of the products would result in the WADA thresholds of E and NPE being exceeded, respectively. Our data provide critical information for athletes and medical personnel, who should be wary of using complex Chinese herbal formulae in addition to over-the-counter products.