Ostarine (enobosarm, GTx-024) is an oral selective androgen receptor modulator (SARM), a non-steroidal compound designed to act on androgen receptors in muscle and bone. It has been studied as an investigational drug for muscle wasting and is not FDA approved.
Also known as: enobosarm, MK-2866, GTx-024.
There is no approved product. Phase 2 trials used 0.1, 0.3, 1 or 3 mg a day for 12 weeks in older adults (Dalton 2011) and 1 or 3 mg a day in people with cancer (Dobs 2013).
Ostarine is not FDA approved; it is an investigational drug. FDA says SARMs are unapproved drugs that cannot be legally marketed in the US as dietary supplements or drugs, and lists risks including liver injury and acute liver failure, a higher risk of heart attack or stroke, and effects on fertility. In a 2017 warning letter FDA said ostarine was not marketed as a supplement or food before it was authorized for investigation as a new drug, so it is excluded from the dietary supplement definition.
In the phase 2 trial in older adults, HDL cholesterol fell with dose, by 17% at 1 mg and 27% at 3 mg, and one person stopped because of a raised liver enzyme (Dalton 2011). These are trial protocols, not personalized advice; confirm any dosing with your prescriber.
We could not find a published human half-life or time to peak for ostarine in the trial reports we opened, so we do not list the app's 24-hour and 1-hour modeling values.