Ostarine (MK-2866, enobosarm) — Research Literature Summary
Class: SARM • Page type: research-literature reference • Updated 2026-04-23
Regulatory notice — research reference only
Ostarine (MK-2866, enobosarm) is an investigational SARM. It has not received FDA approval for any indication. The U.S. FDA and DOJ have explicitly enforced against sale of SARMs for human consumption. This page summarizes published clinical research only.
Published research summary
- Enobosarm is the most clinically studied SARM. It has been evaluated in Phase II and Phase III trials by GTx, Inc. for muscle wasting in cancer cachexia (POWER trials) and stress urinary incontinence, and more recently by Veru Inc. for breast cancer.
- POWER 1 and POWER 2 (Phase III, ~650 NSCLC patients each, 3 mg/day oral for ~4 months) showed improvement in lean body mass versus placebo but did not meet the co-primary stair-climb endpoint required for regulatory approval.
- HPT-axis suppression has been observed at doses >= 1 mg/day; long-term safety data are limited to trial durations.
- Ostarine is prohibited at all times on the WADA Prohibited List (S1.2).
Why this page does not publish a consumer “cycle” schedule
Published research used fixed doses (1-3 mg/day) for defined trial durations. Consumer 'cycle' or 'PCT' protocols are not reflected in the peer-reviewed record.
Peer-reviewed citations
Consulting a healthcare provider: This page is a reference for published research. If you are considering any health decision, consult a licensed healthcare provider. Path to Peptides does not provide medical advice.