Performance Compounds Library

Ostarine vs RAD-140

The table compares the compounds’ key data from their entry pages. Open each compound’s full entry for details. Educational content, not medical advice.

What it is
MK-2866 (Ostarine, Enobosarm)Non-steroidal SARM (Enobosarm), GTx Inc 2007. The SARM with the MOST clinical trial data: Phase II cachexia (Dalton 2011 PMID 21833506, 159 patients), Phase III POWER cancer-cachexia trials (Crawford 2016 PMID 26944362). The most popular SARM on the bodybuilding market, UGL marketing under 'soft first-SARM' label. WADA-banned S1.2.
RAD-140 (Testolone)Non-steroidal SARM (selective androgen receptor modulator) developed by Radius Health in 2010. Phase II clinical trial for breast cancer + cachexia (Flores 2020 PMID 32472247). Strong muscle-building with AR selectivity (muscle > prostate), BUT 2017-2020 hepatotoxicity case reports on UGL use (Hilal 2020 PMID 32492288). WADA-banned.
Mechanism
MK-2866 (Ostarine, Enobosarm)Non-steroidal selective AR modulator (aryl-propionamide). Strong AR agonist in muscle, moderate prostate.
RAD-140 (Testolone)Non-steroidal selective AR modulator (anilide). Strong AR agonist in muscle + bone, weaker in prostate.
Anabolic activity (Dalton 2011)
MK-2866 (Ostarine, Enobosarm)1.3 kg lean body mass gain @ 3 mg/day, 16 weeks, cancer cachexia patients.
RAD-140 (Testolone)
Half-life
MK-2866 (Ostarine, Enobosarm)~24 h (oral)
RAD-140 (Testolone)~16-20 h (oral)
Onset
MK-2866 (Ostarine, Enobosarm)2-4 weeks
RAD-140 (Testolone)1-2 weeks (anecdotal strength gain)
Legal status
MK-2866 (Ostarine, Enobosarm)Never FDA-approved (Phase III POWER failed 2016). UGL 'research chemical'. WADA-banned S1.2.
RAD-140 (Testolone)Never an Rx (Phase II stalled). UGL market 'research chemical'. USA Schedule III analog in some states from 2018. WADA-banned.
Anabolic activity (Miller 2011)
MK-2866 (Ostarine, Enobosarm)
RAD-140 (Testolone)~80% testosterone-level in vivo muscle AR activity, ~30% prostate activity → selectivity ratio ~2.5x