MK-677 (Ibutamoren) vs Tesamorelin
A side-by-side research comparison of MK-677 (Ibutamoren) and Tesamorelin across mechanism, dosing, half-life, benefits, side effects and research status.
Comparison table
| Attribute | MK-677 (Ibutamoren) | Tesamorelin |
|---|---|---|
| Full name | Ibutamoren Mesylate (MK-677) | Tesamorelin Acetate (Egrifta) |
| Category | Growth Hormone | Growth Hormone |
| Status | Investigational | FDA Approved |
| Mechanism | Acts as ghrelin mimetic at GHS-R1a receptors in hypothalamus and pituitary. Excellent oral bioavailability and 24-hour duration. | Binds pituitary GHRH receptors with enhanced affinity via hexenoic acid modification. Effective at mobilizing visceral fat via GH-mediated lipolysis. |
| Molecular weight | 528.7 Da | 5,136 Da |
| Half-life | 24 hours | 26-38 minutes |
| Bioavailability | High (oral) | High (SubQ) |
| Typical dose | 10-25 mg | 2 mg |
| Frequency | Once daily | Once daily |
| Route | Oral (capsule/liquid) | Subcutaneous injection |
MK-677 (Ibutamoren) reported benefits
- Oral administration
- Sustained 24h GH elevation
- Increased IGF-1
- Improved sleep depth
- Enhanced recovery
- Bone density support
Tesamorelin reported benefits
- Visceral fat reduction (up to 18%)
- FDA-approved safety
- Improved lipid panels
- Cognitive benefits (emerging)
- No significant IGF-1 overshoot
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Research and educational reference only. Not medical advice.