MK-677 vs GHRP-6
Head-to-head comparison of MK-677 (Ibutamoren Mesylate (MK-677)) and GHRP-6 (Growth Hormone Releasing Peptide-6) — benefits, dosing, side effects, research data, and where to buy.
| Property | MK-677 | GHRP-6 |
|---|---|---|
| Category | Growth Hormone | Performance |
| Full Name | Ibutamoren Mesylate (MK-677) | Growth Hormone Releasing Peptide-6 |
| Molecular Weight | 528.662 g/mol | 873.01 Da |
| Half-Life | ~24 hours | ~15-60 minutes |
| Amino Acids | Non-peptide compound | 6 |
| Typical Dose | — | 100-300 mcg |
| Route | — | SC / IV |
| Purity | >99% | — |
| Studies Count | 120 | 186 |
| Research Status | Active Research | Clinical Trials |
MK-677 Benefits
- ✓Oral GH secretagogue, 24-hour GH elevation, increases IGF-1, improves sleep quality, increases lean mass, does not suppress natural GH
GHRP-6 Benefits
- ✓Potent GH release stimulation
- ✓Muscle growth and strength
- ✓Appetite stimulation (ghrelin pathway)
- ✓Improved body composition
- ✓Enhanced recovery from training
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.
GHRP-6 Dosing
Standard: 100-300 mcg SC 2-3 times daily|Pre-workout: 100 mcg 30 min before training|Pre-bed: 100-200 mcg for overnight GH pulse
MK-677 Side Effects
- ⚠Increased appetite, mild water retention, drowsiness, transient numbness, mild increase in fasting blood glucose with long-term use.
GHRP-6 Side Effects
- ⚠Common: Increased appetite (significant), water retention, tingling
- ⚠Moderate: Cortisol elevation (dose-dependent), lethargy
- ⚠Rare: Elevated prolactin at high doses
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.
GHRP-6
GHRP-6 has solid pre-clinical and clinical evidence for GH stimulation. Well-characterized pharmacology. More appetite stimulation than Ipamorelin due to ghrelin receptor activation.
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