SARMs

Non-steroidal ligands at the androgen receptor, designed to be tissue-selective — agonists in muscle and bone with less effect on prostate and skin. Ostarine, ligandrol, RAD-140 and andarine are that. Selectivity is the design intent, demonstrated largely in animals; none is an approved medicine, so evidence about what they do in people across months does not exist in the form the marketing implies.

The label is also applied loosely by the market, and two of the best-known members are not SARMs at all: cardarine is a PPARδ agonist, abandoned in development after cancer findings in animals, and YK-11 is a steroidal compound working through a different route. Suppression of endogenous testosterone does happen, contrary to how the class is sold, and liver enzyme elevations and lipid changes are reported. Product analyses repeatedly find contents that do not match the label.