Ostarine

evidence score

sarm

Research Only

152 studies

MK-2866EnobosarmGTx-024+1 more

Ostarine (MK-2866, Enobosarm) is the most clinically studied SARM. Phase II trials completed for cancer cachexia showed significant lean mass gains and improved physical function at 1–3mg/day. Phase III was initiated but not completed. Despite trial history, it remains unapproved. Used widely in the research and fitness communities for muscle preservation, recomposition, and joint support. Suppresses endogenous testosterone in a dose- and duration-dependent manner. WADA-prohibited.

Evidence

Moderate evidence

Safety

Unknown safety profile

Clinical Status

Phase II

Research Sync

Feb 19, 2026

Dosing

Typical

20 mg

10 mgRange30 mg

FrequencyOnce daily oral

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Pharmacology

Half-life~24 hours

Onset2–3 weeks for noticeable muscle effects

DurationEffects persist weeks; suppression recovers over 4–6 weeks post-cycle

Routes

oral

Evidence Score

Level B — Moderate

152 studies indexed · 1 meta-analysis

Scoring Factors

Volume(40%)~44/100

Quality(30%)~45/100

Sample Size(10%)~100/100

Consistency(10%)~100/100

Replication(5%)~100/100

Recency(5%)~100/100

Scores estimated from study counts. Exact breakdown computed after research sync.

Evidence Levels

AScore ≥75 with at least 1 meta-analysis and 3+ RCTs

BScore ≥50 with at least 1 RCT or meta-analysis

CScore ≥25 — observational or animal evidence only

DScore <25 — very limited or preclinical data

Plain-English Snapshot

Ostarine is currently categorized as a sarm compound.

Evidence is moderate (67/100): promising signal from 152 indexed studies, but context and population still matter.

Safety scoring is incomplete. Start conservatively and monitor carefully.

Core mechanism

Selective AR agonist with tissue selectivity for muscle and bone over prostate and sebaceous glands; anabolic without full androgenic activity

Practical Context

Strongest current signals

Level C: Endocrinological aspects of sarcopenic obesity.
Level C: Pharmacologic Treatments for the Preservation of Lean Body Mass During Weight Loss.
Level C: Selective androgen receptor modulators (SARMs) - potential anabolic drugs for the treatment of cachexia and frailty syndrome.