Ostarine, a SARM developed in the 2000s, continues to plague sports

Ostarine, a selective androgen receptor modulator (SARM) first developed by University of Tennessee researcher James Dalton in the early 2000s, has repeatedly turned up in athletes’ drug tests and is still disrupting sports, the New York Times reports (Feb. 2, 2026). The drug’s presence has affected competitors across disciplines and may have cost at least one American athlete a spot on this month’s Winter Games in Italy.

Dalton and his team envisioned the compound as a medicine to build muscle mass in cancer patients, strengthen bones in people with osteoporosis and treat pelvic-muscle weakness; their study was published three years after the initial experiments. The drug showed measurable muscle gains in clinical trials, but it was never approved for human use by the F.D.A.

Instead, ostarine spread through commercial distributors and overseas manufacturers, often sold on slick websites and traced to residential addresses or mailboxes. Regulators seized thousands of pills at U.S. ports in recent years, and officials including former F.D.A. cyber chief Dan Burke said many sellers handled the substance irresponsibly.

Athletes from many sports — including weight lifting, track, snowboarding, mixed martial arts and horse racing — have tested positive, and governing bodies added ostarine to banned-substance lists.

ostarine, sarm, james dalton, university of tennessee, u.s. anti-doping agency, world anti-doping agency, f.d.a, dan burke, ostarine clinical trials, u.s. customs seizures, warrior labz, accelerated genetix, athletes testing positive, winter games italy