S-4

S-4 Product Description — Research Use Only

S-4, also known as Andarine, is a research compound studied as a selective androgen receptor modulator, commonly known as a SARM. It is not a peptide, but it is often grouped within peptide and research-compound catalogs because of its use in androgen-receptor, muscle-support, bone-support, lean-mass, and body-composition research.

Research on S-4 has most commonly focused on androgen receptor activity, tissue-selective anabolic signaling, muscle-support pathways, bone-density research, lean-mass markers, and hormone-response studies. Broader SARM literature describes this compound class as nonsteroidal agents that bind androgen receptors and may show anabolic activity in muscle and bone with reduced activity in some secondary androgen-sensitive tissues compared with traditional androgens.

S-4 is commonly studied for:

• Androgen receptor activity — how the compound interacts with androgen receptor pathways

• Muscle-support pathways — signals connected to muscle maintenance, repair, and protein balance

• Lean-mass research — markers related to lean tissue and body-composition changes

• Bone-support pathways — research involving bone strength, density, and maintenance

• Tissue selectivity — how activity may differ between muscle, bone, and other tissues

• Anabolic signaling — pathways connected to tissue growth, repair, and recovery response

• Hormone-response markers — how androgen-related pathways influence biological signaling

S-4 is commonly studied because SARMs are designed to activate androgen receptor pathways in a more tissue-selective way than traditional steroidal androgens. S-4/Andarine has also appeared in analytical and labeling research involving products marketed as SARMs, where investigators identified it among compounds sold online and emphasized concerns around product-label accuracy and unapproved research-chemical use.

For research use only. Not for human consumption, medical use, diagnostic use, or therapeutic application.