Evidence review: Open Peptide Project (verified against primary PubMed, ClinicalTrials.gov & FDA records) · Last checked 2026-10-27. ← Back to Evidence Library

Enobosarm (ostarine, MK-2866, GTx-024): what the evidence says

Name: Enobosarm (ostarine, MK-2866, GTx-024)
Published: 2026-10-27

At a glance

What it is: Caution Not a peptide. Enobosarm is an oral non-steroidal selective androgen receptor modulator (SARM). It is listed here only because it is sold alongside research peptides. ^R1

What the evidence says: Human in a phase 2 RCT in 159 people with cancer, lean mass rose about 1–1.5 kg over 113 days vs no change on placebo. ^R1 Two phase 3 POWER trials followed ^{R2, R3}; UNVERIFIED reports that they missed the physical-function approval bar (no peer-reviewed results found).

Biggest risks: hormone suppression and liver injury are reported for SARMs; UNVERIFIED enobosarm-specific DILI and HDL figures (not in the abstracts we opened).

Rating


Human Human evidence	Moderate: phase 2 RCT (n = 159) ^R1
Animal Animal / lab evidence	Not reviewed
Regulatory	Not FDA-approved · not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page ^{R4, R5, R6} · named on WADA S1.2 ^R7
Established human dose	No

Evidence verdict: Lean mass in cancer wasting: Moderate (phase 2 RCT) · Physical function: not shown · Bodybuilding: Unknown

This page reports what studies used. It is not dosing advice.

Legend: HUMAN data · ANIMAL / LAB data · UNKNOWN · UNVERIFIED: not yet confirmed against a primary source

About the evidence: lean-mass gains are real in trials but small, and no trial has shown people get stronger or function better in a way regulators accepted.

What is it?

Related pages: lgd-4033, yk-11, mk-677, bimagrumab.

Does it work?

Human Phase 2: +1.0 to +1.5 kg lean mass. ^R1
Unknown POWER 1/2: unpublished results. ^R3
Unknown QUALITY with semaglutide (n = 168): completed, no peer-reviewed results. ^R8

Is it safe?

Human Phase 2: serious events similar to placebo and judged unrelated. ^R1

Pipeline status (investigational)

Sponsor: Veru (current). ^R8
Trials: NCT01355497 POWER (GTx, completed 2013) ^R3; NCT06282458 QUALITY (completed Apr 2025). ^R8
Expected readouts: UNVERIFIED phase 3 plans.

Gray-market vials: extra risks

A gray-market vial has no quality control and no guarantee of identity, strength or sterility. We test retail vials blind under the Open Peptide Standard; see /tests/. A passing test covers one batch on one date and does not mean the compound is safe.

Is it legal?

US: not FDA-approved; no Drugs@FDA application found (openFDA searched Oct 27, 2026).
Compounding: not on FDA's 503A or 503B bulk-substance category lists and not on FDA's compounding safety-risk page. ^{R4, R5, R6}
Sport: WADA 2026 S1.2 names it as a prohibited SARM, banned at all times ^R7.

Study details

These are amounts researchers used, not recommendations.

Study	People / model	Route	Amount used	Follow-up	Reported	Citation
Phase 2 (Dobs 2013)	159 adults with cancer	Oral	1 or 3 mg daily	Up to 113 days	+1.0–1.5 kg lean mass	PMID 23499390

Full reference list (PubMed, CT.gov, FDA and WADA checked Oct 27, 2026)

^R1 Dobs AS, et al. Lancet Oncol. 2013. PMID 23499390
^R2 Crawford J, et al. Curr Oncol Rep. 2016. PMID 27138015
^R3 ClinicalTrials.gov NCT01355497, POWER phase 3 NSCLC cachexia, GTx, completed (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT01355497
^R4 FDA, 503A bulk drug substances categories list (updated May 14, 2026). https://www.fda.gov/media/94155/download
^R5 FDA, 503B bulk drug substances categories list (updated Mar 21, 2025). https://www.fda.gov/media/94164/download
^R6 FDA, Certain bulk drug substances for use in compounding that may present significant safety risks (content current Apr 22, 2026). https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
^R7 WADA. The 2026 Prohibited List, S1.2 Other anabolic agents. https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf
^R8 ClinicalTrials.gov NCT06282458, QUALITY phase 2 with semaglutide, Veru, completed (CT.gov API v2, checked Oct 27, 2026). https://clinicaltrials.gov/study/NCT06282458

Disclaimer

This page is for education and harm reduction, not medical advice or a recommendation to use Enobosarm (ostarine, MK-2866, GTx-024). This is an investigational drug. It is available only inside registered clinical trials; products sold online under this name are unregulated. Report problems to FDA MedWatch (https://www.fda.gov/safety/medwatch).