SARMs

Sarms, or selective androgen receptor modulators, are a class of experimental compounds designed to selectively stimulate androgen receptors in muscle and bone while minimizing activation in other tissues. They were developed to treat conditions such as muscle wasting, osteoporosis, and hypogonadism, with the aim of delivering anabolic benefits with fewer masculinizing or androgenic side effects compared with testosterone.

Mechanism and development: like traditional androgens, SARMs bind to the androgen receptor, but their tissue-selective action is achieved through differences in receptor conformation and cofactor recruitment. This selective activity is intended to promote gains in lean mass and bone density with reduced risk of hair loss, prostate enlargement, or deepening voice.

Examples: MK-2866 (Ostarine), LGD-4033 (Ligandrol), S4 (Andarine), RAD-140 (Testolone), and YK-11. They have undergone preclinical and early clinical research but have not received regulatory approval for medical use in most jurisdictions.

Regulatory status and availability: SARMs are not approved as medicines; many sold online as research chemicals or dietary supplement additives, but regulators warn they may be illegal and unsafe. They are on the World Anti-Doping Agency prohibited list and have been found in dietary supplements marketed to athletes.

Safety and risks: human data are limited. Reported adverse effects include suppression of the hypothalamic-pituitary-gonadal axis, altered lipid profiles, and liver toxicity in some cases, with unknown long-term risks. Quality control and labeling are variable, and dosing is inconsistent.