S-23 Injectable

S23 is a selective androgen receptor modulator that's been being developed for the treatment of muscle wasting, particularly for patients suffering from the muscle-wasting condition called sarcopenia. Sarcopenia is a type of muscle wasting that afflicts older people, and it contributes to disability and death in older people with chronic illness. This new study investigated S23 as a potential male contraceptive drug, in lab rats.

The study authors say that S23 is in a class of compounds called Selective Androgen Receptor Modulators, or SARMs. Like steroids, SARMs are capable of binding to androgen receptors. But SARMs are more selective than steroids, meaning they bind to a specific type of androgen receptor, while avoiding binding to other androgen receptors.