Selective Androgen Receptor Modulators (SARMs) in Sport: Patterns of Use, Product Contamination, Health Risks and Doping-Control Implications.

Selective androgen receptor modulators (SARMs) were developed to reproduce the anabolic effects of testosterone while sparing the prostate, and are marketed as a safer alternative to anabolic steroids. Tissue selectivity is reproducible in preclinical models but largely metabolic in origin and small in humans, and no SARM has been approved in more than 25 years. In randomised trials, lean body mass rises dose-dependently by roughly 1-1.5 kg, with suppression of testosterone, sex hormone-binding globulin and high-density-lipoprotein cholesterol and, with some compounds, reversible rises in aminotransferases, while physical function improves inconsistently. In one randomised-response survey of male gym users, lifetime prevalence was about 2.7%. As used in practice, at higher doses, stacked and unmonitored, the dominant serious harm is a cholestatic drug-induced liver injury, prolonged but usually reversible, with endocrine suppression. In almost all cases, the product was not analysed, so undeclared androgens cannot be excluded. Products sold as SARMs are frequently mislabelled: in one analysis only about half contained a SARM at all, many contained a different unapproved drug, and doses were often wrong. SARMs have been prohibited at all times since 2008. Adverse analytical findings rose from 15 in 2014 to 142 in 2019, then fluctuated (139 in 2023, 106 in 2024), a series shaped by testing volume and screening breadth as well as by use. Most follow deliberate purchase of products sold as SARMs. Findings attributed to contaminated ordinary supplements are documented on limited evidence. We set out the implications for doping control and counselling.