YK-11

YK-11 is a synthetic, steroidal selective androgen receptor modulator (SARM) known for its potent anabolic effects on muscle cells and bone. It functions as a partial agonist of the androgen receptor and also acts as a myostatin inhibitor by increasing the expression of follistatin, a protein that suppresses muscle growth. YK-11 is classified as an experimental compound and has not been approved for medical use in humans. Despite this, it is widely misused in sports as a performance-enhancing drug and is found in dietary supplements. Preclinical studies have investigated its potential in conditions such as muscle wasting, osteoporosis, obesity, and sepsis.

Other names

17α-methyl-δ2-17β-hydroxyestra-4,9-dien-3-one(17α,20E)-17,20-[(1-methoxyethylidene)bis(oxy)]-3-oxo-19-norpregna-4,20-diene-21-carboxylic acid methyl ester