MK-677 vs Cholecystokinin-8
Head-to-head comparison of MK-677 (Ibutamoren Mesylate (MK-677)) and Cholecystokinin-8 (Cholecystokinin (sulfated C-terminal octapeptide, CCK-8)) — benefits, dosing, side effects, research data, and where to buy.
Research Score
| Property | MK-677 | Cholecystokinin-8 |
|---|---|---|
| Category | Growth Hormone | Endocrine Peptides |
| Full Name | Ibutamoren Mesylate (MK-677) | Cholecystokinin (sulfated C-terminal octapeptide, CCK-8) |
| Molecular Weight | 528.662 g/mol | 1143.2 Da |
| Half-Life | ~24 hours | 1-2 min |
| Amino Acids | Non-peptide compound | DY(SO3H)MGWMDF-NH2 |
| Typical Dose | — | physiologic low-picomolar-nanomolar range|research-dependent |
| Route | — | endogenous secretion|research IV/SC |
| Purity | >99% | ≥98% |
| Studies Count | 120 | 97 |
| Research Status | Active Research | Endogenous |
MK-677 Benefits
- ✓Oral GH secretagogue, 24-hour GH elevation, increases IGF-1, improves sleep quality, increases lean mass, does not suppress natural GH
Cholecystokinin-8 Benefits
- ✓gallbladder contraction
- ✓pancreatic enzyme release
- ✓satiety 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.
Cholecystokinin-8 Dosing
physiologic secretion|research-dependent
MK-677 Side Effects
- ⚠Increased appetite, mild water retention, drowsiness, transient numbness, mild increase in fasting blood glucose with long-term use.
Cholecystokinin-8 Side Effects
- ⚠abdominal cramping
- ⚠nausea
- ⚠biliary contraction
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.
Cholecystokinin-8
CCK-8 is a canonical gut hormone fragment with extensive documentation in digestive physiology and appetite control. Sulfation of the tyrosine residue is important for high-affinity receptor activity.
Ready to buy?
Find both peptides from our verified, lab-tested vendors with purity certificates and third-party testing.