Cholecystokinin-8 vs GHRP-2
Head-to-head comparison of Cholecystokinin-8 (Cholecystokinin (sulfated C-terminal octapeptide, CCK-8)) and GHRP-2 (Growth Hormone Releasing Peptide-2) — benefits, dosing, side effects, research data, and where to buy.
Research Score
| Property | Cholecystokinin-8 | GHRP-2 |
|---|---|---|
| Category | Endocrine Peptides | Performance |
| Full Name | Cholecystokinin (sulfated C-terminal octapeptide, CCK-8) | Growth Hormone Releasing Peptide-2 |
| Molecular Weight | 1143.2 Da | 817.97 Da |
| Half-Life | 1-2 min | ~25 minutes |
| Amino Acids | DY(SO3H)MGWMDF-NH2 | 6 |
| Typical Dose | physiologic low-picomolar-nanomolar range|research-dependent | 100-300 mcg |
| Route | endogenous secretion|research IV/SC | SC / IV |
| Purity | ≥98% | — |
| Studies Count | 97 | 172 |
| Research Status | Endogenous | Approved (Japan) |
Cholecystokinin-8 Benefits
- ✓gallbladder contraction
- ✓pancreatic enzyme release
- ✓satiety signaling
GHRP-2 Benefits
- ✓Potent GH release (stronger than GHRP-6)
- ✓Less appetite stimulation than GHRP-6
- ✓Improved body composition
- ✓Enhanced deep sleep quality
- ✓Cytoprotective properties
Cholecystokinin-8 Dosing
physiologic secretion|research-dependent
GHRP-2 Dosing
Standard: 100-300 mcg SC 2-3 times daily|Pre-bed: 100-200 mcg for GH pulse during sleep|Combined: 100 mcg with CJC-1295 for synergy|Cycle: 8-16 weeks, 4 weeks off
Cholecystokinin-8 Side Effects
- ⚠abdominal cramping
- ⚠nausea
- ⚠biliary contraction
GHRP-2 Side Effects
- ⚠Common: Mild appetite increase, water retention, tingling
- ⚠Moderate: Cortisol elevation at higher doses
- ⚠Rare: Prolactin increase, transient dizziness
- ⚠Better tolerated than GHRP-6 overall
Research Overview
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.
GHRP-2
GHRP-2 has strong clinical evidence. Approved in Japan for diagnostic use. Multiple human studies confirm reliable GH stimulation with a favorable side effect profile compared to GHRP-6.
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