Analysis of supplements available to UK consumers purporting to contain selective androgen receptor modulators.

Selective androgen receptor modulators (SARMs) are compounds with specific androgenic properties investigated for the treatment of conditions such as muscle wasting diseases. The reported androgenic properties have resulted in their use by athletes, and consequently they have been on the World Anti-Doping Agency prohibited list for more than a decade. SARMs have been investigated by pharmaceutical companies as potential drug candidates, but to date no SARM has demonstrated sufficient safety and efficacy to gain clinical approval by either the European Medicines Agency or the U.S. Food and Drug Administration. Despite their lack of safety approval, SARMs are often illegally marketed as dietary supplements, available for consumers to buy online. In this study, a range of supplement products marketed as SARMs were purchased and analyzed using high resolution accurate mass - mass spectrometry to evaluate the accuracy of product claims and content labeling. This study found discrepancies ranging from a supplement in which no active ingredients were found, to supplements containing undeclared prohibited analytes. Where SARMs were detected, discrepancies were observed between the concentrations measured and those detailed on the product packaging. The outcome of this experiment highlights the high risk of such supplement products to consumers. The inaccurate product claims give rise to uncertainty over both the dose taken and the identity of any of these unapproved drugs. Even for supplements for which the product labeling is correct, the lack of complete toxicity data, especially for combinations of SARMs taken as stacks, means that the safety of these supplements is unknown.