S-23 is an investigational

selective androgen receptor modulator Selective Androgen Receptor Modulators or SARMs are a class of androgen receptor ligands that maintain some of the desirable effects of androgens, such as preventing osteoporosis and muscle loss while reducing risks of developing prostate cancer ...

(SARM) developed by GTX, Inc as a potential

male hormonal contraceptive Male contraceptives, also known as male birth control, are methods of preventing pregnancy that solely involve the male physiology. The most common kinds of male contraception include condoms, outercourse, and vasectomy. In domestic animals, cas ...

. It binds to the

androgen receptor The androgen receptor (AR), also known as NR3C4 (nuclear receptor subfamily 3, group C, member 4), is a type of nuclear receptor that is activated by binding any of the androgenic hormones, including testosterone and dihydrotestosterone in th ...

more strongly than older drugs such as

andarine Andarine (developmental code names GTx-007, S-4) is an investigational selective androgen receptor modulator (SARM) developed by GTX, Inc for treatment of conditions such as muscle wasting, osteoporosis and benign prostatic hypertrophy, using th ...

with a K_i of 1.7 nM, and in animal studies it showed both a good ratio of

anabolic Anabolism () is the set of metabolic pathways that construct molecules from smaller units. These reactions require energy, known also as an endergonic process. Anabolism is the building-up aspect of metabolism, whereas catabolism is the breaking-do ...

androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This inc ...

ic effects, and dose-dependent suppression of

spermatogenesis Spermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubule ...

with spontaneous recovery after cessation of treatment.

References

Anilides Tertiary alcohols Chloroarenes Fluoroarenes Nitriles Phenol ethers Selective androgen receptor modulators Trifluoromethyl compounds {{genito-urinary-drug-stub