Enobosarm

Enobosarm, also called ostarine or GTx-024, is an unapproved androgen-receptor SARM with short lean-mass signals and split registry-posted phase 3 lean-mass and function results.

tier D · androgens · 159 / 100 randomized and efficacy-evaluable phase 2 denominators

verdict

Short randomized trials found lean-mass changes in selected older and cancer populations. POWER1 and POWER2 posted split lean-mass and stair-power responder patterns, and the record does not establish durable function, survival, athletic benefit, or long-term safety.

the core tension

Enobosarm repeatedly changes lean mass, but its clinical story breaks at the function boundary. Phase 3 outcomes remain registry-posted and sponsor-interpreted rather than a full peer-reviewed outcomes analysis, and no approved long-term safety framework exists.

what it is

Enobosarm is a nonsteroidal selective androgen-receptor modulator, or SARM. Its aliases include ostarine, GTx-024, MK-2866, and S-22. It is distinct from ligandrol and from an unverified product sold under an alias.

what it does

It binds the androgen receptor and produces tissue- and coregulator-dependent signaling. Human lean-mass changes confirm anabolic pharmacology, but claimed tissue selectivity does not remove androgen-axis or organ-safety uncertainty.

origin

No FDA-approved enobosarm product exists. The peer-reviewed POWER design and rationale paper is not a full outcomes publication. POWER outcomes are registry-posted, while the statement that neither trial met both co-primary criteria is SEC-reported sponsor disclosure.

does it work

A 120-person older-adult study found a short lean-mass and stair-power signal at its highest studied group. A cancer study randomized 159 people but reported efficacy in 100 evaluable participants. Its headline lean-mass changes were within-group results, not an unqualified between-group clinical benefit.

key facts

• molecular formula: C19H14F3N3O3
• molecular weight: 389.3287 g/mol
• amino acids: n/a (nonsteroidal small molecule, not a peptide)
• half-life: not stated; no complete source-backed base PK set in the cited public outcome record
• type: nonsteroidal selective androgen-receptor modulator
• CAS: 841205-47-8
• 159 randomized in the cancer phase 2 study
• 100 efficacy-evaluable in that study
• 651 combined actual enrollment in POWER1 and POWER2

frequently asked questions

Is enobosarm FDA approved?

No. FDA treats SARM products as unapproved drugs, and a current warning letter names MK-2866, ostarine, and enobosarm.

Did phase 3 prove it works for cancer cachexia?

No. POWER1 and POWER2 have registry-posted responder percentages, not a full peer-reviewed outcomes paper. Function and lean-mass patterns split, and the sponsor reported that neither trial met both co-primary criteria.

Does more lean mass mean better function?

No. POWER2 is the clearest warning: lean-mass response numerically favored enobosarm while stair-power response numerically favored placebo.

What is the human half-life?

This page does not publish one. The public outcome papers do not provide a complete general PK set, and the drug-interaction abstract does not supply a standalone base profile.

Are products labeled ostarine equivalent to the trials?

No. A name on a supplement, liquid, or research product does not establish identity, purity, strength, formulation, or trial-equivalent exposure.

related peptides

• Ligandrol: The enobosarm evidence cited on this page does not establish ligandrol's identity, approval, trial record, or outcomes.
• testosterone: The enobosarm evidence cited on this page does not establish testosterone's approval, safety framework, or outcomes.

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.