ACE-031 vs MK-2866 (Ostarine)
A side-by-side research comparison of ACE-031 and MK-2866 (Ostarine) across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | ACE-031 | MK-2866 (Ostarine) |
|---|---|---|
| Full name | ACE-031 (Soluble ActRIIB-Fc Fusion) | Ostarine / Enobosarm (MK-2866) |
| Category | Muscle Growth | Muscle Growth |
| Status | Investigational | Investigational (not approved; banned in sport) |
| Mechanism | Decoy receptor sequestering TGF-B ligands (myostatin, activin, GDF-11) in bloodstream, preventing cell-surface ActRIIB binding and removing multiple anabolic brakes. | Selectively binds androgen receptors in muscle and bone tissue, stimulating anabolic (muscle-building) signaling while having relatively less effect on the prostate and other androgen-sensitive tissues than testosterone. |
| Molecular weight | ~90,000 Da | 389.33 Da |
| Half-life | 10-14 days | ~24 hours |
| Bioavailability | High (SubQ) | Oral |
| Typical dose | 0.3-3 mg/kg | Commonly cited 10-25 mg/day (research) |
| Frequency | Every 2-4 weeks | Once daily |
| Route | Subcutaneous | Oral |
ACE-031 reported benefits
- Multi-ligand pathway inhibition
- Lean mass increase
- Bone density increase
- Infrequent dosing
- Functional strength improvement
MK-2866 (Ostarine) reported benefits
- Lean muscle preservation/gain
- Bone density support (research)
- Less androgenic than steroids
- Studied for muscle wasting
Related comparisons
Research and educational reference only. Not medical advice.