Seven herbal products marketed for the treatment of erectile dysfunction were purchased via the Internet (n = 6) or at a local health food store (n = 1). Specimens were analyzed by high performance liquid chromatography and mass spectrometry to detect the presence of sildenafil (Viagra), tadalafil (Cialis) or vardenafil (Levitra). Of the 7 products tested, 1 contained a pharmacological dose of sildenafil (30 mg) and 1 contained a pharmacological dose of tadalafil (20 mg). It was not stated whether the product obtained from the health food store was one of the adulterated products.

Comment: This study indicates that some herbal products sold via the Internet for erectile dysfunction (ED) are adulterated with prescription ED drugs. While true herbal ED products are relatively safe, sildenafil and tadalafil can cause serious adverse reactions in people with cardiovascular disease. In addition, these drugs can interact with a wide range of other prescription medications, and have caused hypotension, shock, or death when used in combination with nitrates. There are many legitimate herbal products on the market, including ones promoted for ED. It would be prudent, however, to avoid purchasing such products from the Internet, unless they are being sold by a company that has been in business for a long time and has an established reputation for selling high-quality products.

Fleshner N, Harvey M, Adomat H, et al. Evidence for contamination of herbal erectile dysfunction products with phosphodiesterase type 5 inhibitors. J Urol 2005;174:636-641.