Side-by-side · Research reference
GHRP-2vsHexarelin
Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.
APhase 2Reviewed15/42 cited
BPhase 1Reviewed19/45 cited
GHRP-2
Hexapeptide GHRP · Phase 2 (clinical diagnostic)
SQ · Multiple sites · 1–3×/day
Hexarelin
Hexapeptide GHRP · Cardio-tropic
SQ · Multiple sites · 1–3×/day
01Mechanism of Action
Parameter
GHRP-2
Hexarelin
Primary target
Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990
Ghrelin receptor (GHS-R1a) + cardiac CD36Smith 1996Ghigo 1997
Pathway
GHS-R1a → Gαq → Ca²⁺ → GH vesicle exocytosisBowers 2002
GHS-R1a → Gαq → Ca²⁺ → GH release. CD36 engagement → direct cardio-tropic actionGhigo 1997
Downstream effect
Strong GH pulse + IGF-1 elevation; appetite increase via ghrelin agonismBowers 2002
Strong GH pulse + IGF-1 elevation; cardio-protective effects in animal MI modelsGhigo 1997
Feedback intact?
Yes, with somatostatin feedback active
Yes initially; tachyphylaxis with chronic useGhigo 1997
Origin
Synthetic hexapeptide; developed by Bowers/Tulane group in the 1980sBowers 1990
Synthetic hexapeptide His-D-2-Methyl-Trp-Ala-Trp-D-Phe-Lys-NH₂Smith 1996
Antibody development
—
—
02Dosage Protocols
Parameter
GHRP-2
Hexarelin
Frequency
1–3× per day
1–2× per day max (tachyphylaxis with chronic 3× daily)
Lower / starter dose
50 mcg per dose
50 mcg per dose
Evidence basis
Phase 2 + clinical diagnostic useBowers 1990
Phase 1 / Phase 2 trialsSmith 1996Ghigo 1997
Duration
8–12 weeks on / 4 off (anecdotal)
4–8 weeks on / 4–8 weeks off (tachyphylaxis mitigation)
Reconstitution
Bacteriostatic water
Bacteriostatic water
Timing
Pre-sleep + fasted preferred
Pre-sleep + fasted preferred
04Side Effects & Safety
Parameter
GHRP-2
Hexarelin
Hunger
Strong appetite increase
Strong appetite increase via ghrelin agonism
Injection site reaction
Mild erythema
—
IGF-1 elevation
Strong; monitor with chronic high-dose use
Strong; monitor with chronic high-dose use
Cancer risk
Contraindicated in active malignancy
Contraindicated in active malignancy (GH/IGF-1 axis)
Pregnancy / OB
Avoid
Avoid
Absolute Contraindications
GHRP-2
- ·Active malignancy
- ·Pregnancy / breastfeeding
Hexarelin
- ·Active malignancy
- ·Pregnancy / breastfeeding
- ·Disrupted hypothalamic-pituitary axis
Relative Contraindications
GHRP-2
- ·Untreated diabetes
Hexarelin
- ·Untreated diabetes
- ·Severe hyperprolactinemia
05Administration Protocol
Parameter
GHRP-2
Hexarelin
1. Reconstitution
Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL.
Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL = 250 mcg per 0.1 mL.
2. Injection site
SQ — abdomen or thigh. Rotate sites.
SQ — abdomen or thigh. Rotate sites.
3. Timing
Pre-sleep + fasted preferred.
Pre-sleep + fasted preferred. Cycle on/off to avoid tachyphylaxis.
4. Storage
Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.
Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.
5. Needle
29–31G, 4–8 mm insulin syringe.
29–31G, 4–8 mm insulin syringe.
06Stack Synergy
GHRP-2
+ CJC-1295 (no DAC)
StrongGHRP-2 + CJC-1295-no-DAC is a higher-amplitude alternative to the ipamorelin + CJC-1295 stack. GHRP-2 produces a stronger pulse but with cortisol + prolactin signal — choose when maximum GH amplitude is the goal and the side-effect tolerance is acceptable.
- GHRP-2
- 100–200 mcg SQ · pre-sleep
- CJC-1295 (no DAC)
- 100 mcg SQ · same injection
- Primary benefit
- High-amplitude GH pulse, body composition
Hexarelin
+ CJC-1295 (no DAC)
StrongHexarelin (GHRP) + CJC-1295-no-DAC (GHRH analogue) is the higher-amplitude variant of the standard GHRH+GHRP stack. Hexarelin produces a stronger pulse than ipamorelin but with cortisol + prolactin signal — choose this stack for maximum GH amplitude when side-effect tolerance is acceptable. Cycle aggressively.
- Hexarelin
- 100 mcg SQ · pre-sleep
- CJC-1295 (no DAC)
- 100 mcg SQ · same injection
- Primary benefit
- Maximum GH pulse amplitude (with side-effect signal)