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Specimen Atlas of Research Peptides30 plates · MIT
PeptidesDBan atlas
Side-by-side · Research reference

GHRP-2vsIpamorelin

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 1Reviewed21/57 cited
GHRP-2
Hexapeptide GHRP · Phase 2 (clinical diagnostic)
100–300 mcgPer doseBowers 1990
Phase 2Evidence levelBowers 1990Sigalos 2018
~30 minHalf-lifeMalagón 1999
SQ · Multiple sites · 1–3×/day
Ipamorelin
Selective GHRP · Ghrelin Mimetic
200–300 mcgPer doseRaun 1998
Phase 1Evidence levelRaun 1998Sigalos 2018
~2 hrHalf-lifeRaun 1998
SQ · Multiple sites · 1–3×/day

01Mechanism of Action

Parameter
GHRP-2
Ipamorelin
Primary target
Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990
Ghrelin receptor (GHS-R1a) on anterior pituitaryRaun 1998
Pathway
GHS-R1a → Gαq → Ca²⁺ → GH vesicle exocytosisBowers 2002
GHS-R1a binding → Gαq/11 → ↑intracellular Ca²⁺ → GH vesicle exocytosisRaun 1998Bowers 1991
Downstream effect
Strong GH pulse + IGF-1 elevation; appetite increase via ghrelin agonismBowers 2002
GH pulse amplification, IGF-1 elevation, recovery and lipolytic effectsBowers 2002
Feedback intact?
Yes, with somatostatin feedback active
Yes — pulsatile pattern preserved; somatostatin feedback activeBowers 2002
Origin
Synthetic hexapeptide; developed by Bowers/Tulane group in the 1980sBowers 1990
Pentapeptide H-Aib-His-D-2-Nal-D-Phe-Lys-NH₂; rationally designed for ghrelin-receptor selectivityRaun 1998
Antibody development
—
Not reported in short-term studies

02Dosage Protocols

Parameter
GHRP-2
Ipamorelin
Standard dose
100–300 mcg per injectionBowers 1990
200–300 mcg per injectionRaun 1998
Anecdotal community range; clinical doses 1–3 mg IV in trials.
Frequency
1–3× per day
1–3× per day
Once daily pre-sleep is most common; twice or thrice for advanced users.
Lower / starter dose
50 mcg per dose
100 mcg per dose
Evidence basis
Phase 2 + clinical diagnostic useBowers 1990
Phase 1 + clinical practiceRaun 1998Sigalos 2018
Duration
8–12 weeks on / 4 off (anecdotal)
8–12 weeks on / 4 weeks off (anecdotal)
GHS-R desensitisation reported with continuous dosing.
Reconstitution
Bacteriostatic water
Bacteriostatic water; typical 2 mL per 5 mg vial
Timing
Pre-sleep + fasted preferred
Pre-sleep + fasted preferred; 30 min away from food
Half-life
~30 minMalagón 1999
~2 hoursRaun 1998
Longer than GHRP-6 (15 min); shorter than CJC-1295-DAC (~8 days).

04Side Effects & Safety

Parameter
GHRP-2
Ipamorelin
Cortisol elevation
Mild but measurableBowers 1990
Negligible vs other GHRPsRaun 1998
Prolactin elevation
Mild but measurable
NegligibleRaun 1998
Hunger
Strong appetite increase
Mild appetite increase via ghrelin-receptor crosstalk
Injection site reaction
Mild erythema
Mild irritation possible
IGF-1 elevation
Strong; monitor with chronic high-dose use
Dose-dependent; monitor with chronic high-dose use
Cancer risk
Contraindicated in active malignancy
Theoretical via GH/IGF-1 axis; contraindicated in active malignancy
Pregnancy / OB
Avoid
Avoid
GH excess (overdose)
—
Joint pain, edema, insulin resistance
Absolute Contraindications
GHRP-2
  • ·Active malignancy
  • ·Pregnancy / breastfeeding
Ipamorelin
  • ·Active malignancy or cancer history
  • ·Pregnancy / breastfeeding
  • ·Disrupted hypothalamic-pituitary axis
Relative Contraindications
GHRP-2
  • ·Untreated diabetes
Ipamorelin
  • ·Untreated diabetes
  • ·Severe insulin resistance
  • ·Concurrent corticosteroid use (theoretical desensitisation)

05Administration Protocol

Parameter
GHRP-2
Ipamorelin
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. Roll gently. Solution should be clear.
2. Injection site
SQ — abdomen or thigh. Rotate sites.
Subcutaneous, abdomen or thigh. Rotate sites. Pinch fat for shallow SQ delivery.
3. Timing
Pre-sleep + fasted preferred.
Pre-sleep optimal — aligns with natural GH pulse. Some protocols add a morning fasted dose.
4. Storage
Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.
Lyophilised: room temp, protected from light. Reconstituted: refrigerate 2–8 °C, use within 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)
Strong
View CJC-1295 (no DAC) →

GHRP-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
Bowers 1990Teichman 2006
Ipamorelin
+ Tesamorelin
Strong
View Tesamorelin →

Ipamorelin (GHRP) + tesamorelin (GHRH analogue) is the textbook dual-axis GH stack. They activate two distinct pituitary receptors — the ghrelin receptor and the GHRH receptor — producing a synergistic GH pulse larger than either alone. Ipamorelin's selectivity (no cortisol/prolactin spike) makes it the ideal GHRP partner for long-term protocols.

Ipamorelin
200–300 mcg SQ · pre-sleep
Tesamorelin
2 mg SQ · same injection · pre-sleep
Primary benefit
Maximal GH pulsatility, fat loss, recovery, sleep depth
Raun 1998Bowers 2002
+ CJC-1295 (no DAC)
Strong
View CJC-1295 (no DAC) →

CJC-1295 (no DAC) is a short-acting GHRH analogue. Combined with ipamorelin (GHRP), the pulse is amplified across both receptor systems with timing similar to native physiology. Without the DAC modification, the stack maintains sharp peaks rather than the sustained elevation seen with CJC-1295-DAC + ipamorelin.

Ipamorelin
200–300 mcg SQ · pre-sleep
CJC-1295 (no DAC)
100 mcg SQ · same injection
Primary benefit
Pulsatile GH stimulation matching physiological pattern
Teichman 2006Ionescu 2006