MK-677 vs Ghrelin
Head-to-head comparison of MK-677 (Ibutamoren Mesylate (MK-677)) and Ghrelin (Ghrelin (acylated human ghrelin; endogenous growth hormone secretagogue)) — benefits, dosing, side effects, research data, and where to buy.
| Property | MK-677 | Ghrelin |
|---|---|---|
| Category | Growth Hormone | Growth Hormone |
| Full Name | Ibutamoren Mesylate (MK-677) | Ghrelin (acylated human ghrelin; endogenous growth hormone secretagogue) |
| Molecular Weight | 528.662 g/mol | 3367 Da |
| Half-Life | ~24 hours | 20-30 minutes |
| Amino Acids | Non-peptide compound | 28 |
| Typical Dose | — | 1-3 mcg/kg |
| Route | — | Subcutaneous/Intravenous |
| Purity | >99% | ≥98% |
| Studies Count | 120 | 2000 |
| Research Status | Active Research | Clinical research |
MK-677 Benefits
- ✓Oral GH secretagogue, 24-hour GH elevation, increases IGF-1, improves sleep quality, increases lean mass, does not suppress natural GH
Ghrelin Benefits
- ✓increases GH pulses
- ✓supports appetite and energy intake
- ✓may support lean mass preservation
- ✓promotes recovery signaling
MK-677 Dosing
10-25 mg orally once daily before bedtime. 25 mg is the most studied dose. Can be used long-term without cycling.
Ghrelin Dosing
1-3 mcg/kg SC or IV|repeat dosing in short research windows|titrate to GH response in monitored studies
MK-677 Side Effects
- ⚠Increased appetite, mild water retention, drowsiness, transient numbness, mild increase in fasting blood glucose with long-term use.
Ghrelin Side Effects
- ⚠hunger/nausea
- ⚠transient flushing
- ⚠changes in glucose/insulin
Research Overview
MK-677
A landmark 2-year study in elderly adults demonstrated significant increases in lean mass, GH pulsatility, and IGF-1 to youthful ranges. Selectively agonizes GHS-R1a without increasing cortisol or prolactin.
Ghrelin
Ghrelin is the canonical ligand for the growth hormone secretagogue receptor and is used extensively as a reference compound in GH-axis research. Human and animal studies consistently show rapid, dose-dependent GH release after acyl-ghrelin administration.
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