S23 is a selective androgen receptor modulator (SARM) commonly used in scientific and pharmaceutical research. It serves as a key compound in studies focused on muscle growth, bone health, and treating conditions like muscle wasting (cachexia), sarcopenia, and potentially hormone-dependent cancers. S23 exhibits high selectivity for androgen receptors, promoting anabolic effects with reduced androgenic side effects compared to traditional steroids. It is employed in in vitro and in vivo experiments to assess receptor binding, gene expression, and therapeutic potential in endocrinology and oncology. Due to its niche role in drug discovery, S23 is not approved for clinical use but remains valuable for preclinical research and development of novel therapeutics.