IGF-1 LR3 vs MK-2866 (Ostarine)
A side-by-side research comparison of IGF-1 LR3 and MK-2866 (Ostarine) across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | IGF-1 LR3 | MK-2866 (Ostarine) |
|---|---|---|
| Full name | Insulin-like Growth Factor-1 Long R3 | Ostarine / Enobosarm (MK-2866) |
| Category | Muscle Growth | Muscle Growth |
| Status | Research compound | Investigational (not approved; banned in sport) |
| Mechanism | Activates IGF-1R while evading IGFBP sequestration. Triggers PI3K/Akt/mTOR for protein synthesis, satellite cell proliferation, and amino acid uptake into muscle. | 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 | 9,111 Da | 389.33 Da |
| Half-life | 20-30 hours (vs 15 min native) | ~24 hours |
| Bioavailability | High (SubQ/IM) | Oral |
| Typical dose | 20-50 mcg | Commonly cited 10-25 mg/day (research) |
| Frequency | Daily (post-workout) | Once daily |
| Route | Subcutaneous or intramuscular injection | Oral |
IGF-1 LR3 reported benefits
- Potent anabolic effects
- Hyperplasia (new muscle cells)
- Extended half-life
- Enhanced recovery
- Improved nutrient partitioning
- Satellite cell activation
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.