Orexin-A vs GHRP-2
Head-to-head comparison of Orexin-A (Hypocretin-1 (Orexin-A)) and GHRP-2 (Growth Hormone Releasing Peptide-2) — benefits, dosing, side effects, research data, and where to buy.
| Property | Orexin-A | GHRP-2 |
|---|---|---|
| Category | Cognitive Enhancement | Performance |
| Full Name | Hypocretin-1 (Orexin-A) | Growth Hormone Releasing Peptide-2 |
| Molecular Weight | 3562 Da | 817.97 Da |
| Half-Life | Minutes to <1 hour | ~25 minutes |
| Amino Acids | 33 | 6 |
| Typical Dose | Research-only; no validated human dose | 100-300 mcg |
| Route | Intracerebroventricular/Intranasal | SC / IV |
| Purity | ≥98% | — |
| Studies Count | 42 | 172 |
| Research Status | Pre-clinical | Approved (Japan) |
Orexin-A Benefits
- ✓wakefulness
- ✓attention
- ✓memory consolidation
- ✓fatigue resistance
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
Orexin-A Dosing
Research-only i.c.v. microgram/nanomolar studies|intranasal experimental use|no established human protocol
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
Orexin-A Side Effects
- ⚠insomnia
- ⚠headache
- ⚠blood pressure changes
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
Orexin-A
Preclinical studies link orexin signaling to arousal, learning, and memory consolidation, making orexin-A a candidate for cognition-related research. It is not an approved cognitive enhancer and remains an experimental peptide.
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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