SARM
Selective Androgen Receptor Modulator — a class of compounds that bind androgen receptors in a tissue-selective manner, distinct from and not classified as peptides.
SARMs are synthetic ligands designed to activate androgen receptors preferentially in muscle and bone while minimizing androgenic effects in other tissues like the prostate and skin. Examples include Ostarine (MK-2866), LGD-4033, and RAD-140. Despite being grouped with peptides in biohacking communities, SARMs are small molecules — not peptide chains — and work through a fundamentally different mechanism.
SARMs are not peptides. They suppress endogenous testosterone production to varying degrees, which is why post-cycle therapy (PCT) protocols are commonly discussed alongside their use. Their regulatory status varies by jurisdiction; most are not approved for human use.