Side-by-side · Research reference
GHRP-2vsSermorelin
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 3Reviewed14/43 cited
GHRP-2
Hexapeptide GHRP · Phase 2 (clinical diagnostic)
SQ · Multiple sites · 1–3×/day
Sermorelin
GHRH 1-29 fragment · Short-acting
SQ · Pre-sleep · 1×/day
01Mechanism of Action
Parameter
GHRP-2
Sermorelin
Primary target
Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990
Pituitary GHRH receptorWalker 1994
Pathway
GHS-R1a → Gαq → Ca²⁺ → GH vesicle exocytosisBowers 2002
GHRH-R → Gαs → cAMP → PKA → GH vesicle exocytosisWalker 1994
Downstream effect
Strong GH pulse + IGF-1 elevation; appetite increase via ghrelin agonismBowers 2002
Pulsatile GH release; subsequent IGF-1 elevationMolteno 2013
Feedback intact?
Yes, with somatostatin feedback active
Yes — short pulse preserves feedback
Origin
Synthetic hexapeptide; developed by Bowers/Tulane group in the 1980sBowers 1990
Unmodified active 29-AA fragment of human GHRH (1-44)Walker 1994
Antibody development
—
—
02Dosage Protocols
Parameter
GHRP-2
Sermorelin
Frequency
1–3× per day
Once daily, pre-sleep
Lower / starter dose
50 mcg per dose
100 mcg per dose
Evidence basis
Phase 2 + clinical diagnostic useBowers 1990
Phase 3 (Geref pediatric); clinical practiceWalker 1994Molteno 2013
Duration
8–12 weeks on / 4 off (anecdotal)
8–12 weeks per cycle
Reconstitution
Bacteriostatic water
Bacteriostatic water
Timing
Pre-sleep + fasted preferred
Pre-sleep, fasted preferred
Half-life
~30 minMalagón 1999
~12 min (plasma)Molteno 2013
Shorter than tesamorelin (~26 min) — simpler GHRH analogue.
04Side Effects & Safety
Parameter
GHRP-2
Sermorelin
Prolactin elevation
Mild but measurable
—
Hunger
Strong appetite increase
—
Injection site reaction
Mild erythema
Mild erythema, transient pain
IGF-1 elevation
Strong; monitor with chronic high-dose use
Modest at standard doses
Cancer risk
Contraindicated in active malignancy
Contraindicated in active malignancy (GH/IGF-1 axis)
Pregnancy / OB
Avoid
Avoid
Flushing / headache
—
Common transient effect
Glucose handling
—
Generally neutral
Absolute Contraindications
GHRP-2
- ·Active malignancy
- ·Pregnancy / breastfeeding
Sermorelin
- ·Active malignancy
- ·Pregnancy / breastfeeding
- ·Disrupted hypothalamic-pituitary axis
Relative Contraindications
GHRP-2
- ·Untreated diabetes
Sermorelin
- ·Untreated diabetes
05Administration Protocol
Parameter
GHRP-2
Sermorelin
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.
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
Sermorelin
+ Ipamorelin
StrongSermorelin (GHRH analogue) and ipamorelin (selective GHRP) form the prototypical GHRH+GHRP dual-axis stack at the lowest cost. Both peak within 30 min and produce a sharp physiological GH pulse without cortisol/prolactin elevation.
- Sermorelin
- 200–300 mcg SQ · pre-sleep
- Ipamorelin
- 200–300 mcg SQ · same injection
- Primary benefit
- Pulsatile GH stimulation, recovery, body composition