Selective Androgen Receptor Modulators (SARMs) are a class of therapeutic compounds that have similar anabolic properties to anabolic steroids, but with fewer androgenic properties. They are synthetic chemicals that mimic the effects of androgens, which are natural male sex hormones. SARMs are being evaluated as a clinical treatment for muscle-wasting caused by several diseases, such as osteoporosis, cancer, heart failure, chronic obstructive pulmonary disease, end-stage liver disease, end-stage renal disease, and HIV. In medical settings, SARMs could be useful for stimulating specific tissue growth like muscle and bone, while avoiding unwanted side effects in other tissues like the liver or skin. Examples of SARMs include ostarine (Enobosarm, MK 2866), andarine, LGD-4033 (ligandrol), and RAD140.

SARMs have become popular among fitness enthusiasts, bodybuilders, and those with physically demanding jobs, as they can increase muscle strength and lower the amount of time muscles need to rest after exertion. However, SARMs are not approved for medical or supplemental use in the U.S. . They are unregulated and are still being studied, and much of the evidence regarding their performance-enhancing benefits and overall safety is anecdotal rather than founded on scientific investigation. SARMs can increase the risk of serious side effects, such as increased risk of heart attack or stroke, psychosis/hallucinations, sleep disturbances, sexual dysfunction, liver injury and acute liver failure, infertility, pregnancy miscarriage, and testicular shrinkage.

SARMs are considered unapproved drugs and cannot be legally marketed in the U.S. as a dietary supplement or drug at this time. The World Anti-Doping Agency (WADA) and National Collegiate Athletic Association (NCAA) prohibit SARMs for use in sport, and all SARMs are also on the DoD Prohibited Dietary Supplement Ingredients list. Therefore, it is important to talk to a healthcare professional before considering the use of SARMs.