Side-by-side · Research reference

GHRP-2vsGLP-1 (7-37)

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2HUMAN-REVIEWED15/42 cited

BHuman-MechanisticHUMAN-REVIEWED16/43 cited

GHRP-2

Hexapeptide GHRP · Phase 2 (clinical diagnostic)

100–300 mcgPer doseBowers 1990

Phase 2Evidence levelBowers 1990 Sigalos 2018

~30 minHalf-lifeMalagón 1999

SQ · Multiple sites · 1–3×/day

GLP-1 (7-37)

Incretin Hormone · Native Peptide

~2 minHalf-lifeAlavi 2021 Ding 2017

3297.7 DaMolecular weightAlavi 2021

1922Discovery year

Research use only · IV/SC in experimental settings

01Mechanism of Action

Parameter

GHRP-2

GLP-1 (7-37)

Primary target

Ghrelin receptor (GHS-R1a) on anterior pituitaryBowers 1990

GLP-1 receptor (class B GPCR)Koole 2015

Pathway

GHS-R1a → Gαq → Ca²⁺ → GH vesicle exocytosisBowers 2002

GLP-1R activation → cAMP production → PKA signaling → insulin secretion (pancreatic β-cells)Lu 2025 Koole 2015

Downstream effect

Strong GH pulse + IGF-1 elevation; appetite increase via ghrelin agonismBowers 2002

Glucose-dependent insulin release, glucagon suppression, delayed gastric emptying, reduced food intakeLu 2025 Ding 2017

Feedback intact?

Yes, with somatostatin feedback active

Yes — physiological secretion and degradation preserved

Origin

Synthetic hexapeptide; developed by Bowers/Tulane group in the 1980sBowers 1990

Endogenous peptide cleaved from proglucagon in intestinal L cells; secreted postprandially

Antibody development

—

02Dosage Protocols

Parameter

GHRP-2

GLP-1 (7-37)

Standard dose

100–300 mcg per injectionBowers 1990

—

Frequency

1–3× per day

—

Lower / starter dose

50 mcg per dose

—

Evidence basis

Phase 2 + clinical diagnostic useBowers 1990

—

Duration

8–12 weeks on / 4 off (anecdotal)

—

Reconstitution

Bacteriostatic water

—

Timing

Pre-sleep + fasted preferred

—

Half-life

~30 minMalagón 1999

~2 minutes (plasma)Alavi 2021 Ding 2017

Requires continuous infusion for sustained effect.

Clinical use

—

None — native GLP-1 not used therapeutically

Engineered analogues (semaglutide, liraglutide) used clinically.Friedman 2024

Research dosing

—

Variable — 0.1–10 nmol/kg in animal models

Used as reference standard for analogue comparison.

Modified analogues

—

t½ extended to 13 h (liraglutide), 165 h (semaglutide)

Via DPP-4 resistance + fatty acid acylation.

03Metabolic / Fat Loss Evidence

Parameter

GHRP-2

GLP-1 (7-37)

Mechanism

—

GLP-1R activation in hypothalamic satiety centers (arcuate nucleus) reduces food intakeLu 2025

Effect demonstrated with long-acting analogues (liraglutide).Lu 2025

Native GLP-1 efficacy

—

Minimal — rapid degradation prevents sustained appetite suppression

Gastric emptying

—

Delayed in animal models, contributing to satiety

Body weight impact

—

Not observed with native GLP-1 — requires analogue formulations

04Side Effects & Safety

Parameter

GHRP-2

GLP-1 (7-37)

Cortisol elevation

Mild but measurableBowers 1990

—

Prolactin elevation

Mild but measurable

—

Hunger

Strong appetite increase

—

Injection site reaction

Mild erythema

—

IGF-1 elevation

Strong; monitor with chronic high-dose use

—

Cancer risk

Contraindicated in active malignancy

—

Pregnancy / OB

Avoid

—

Native GLP-1

—

Well-tolerated in research settings; no prolonged exposure data

Hypoglycemia risk

—

Low — insulin secretion is glucose-dependent

Analogue side effects

—

Nausea, vomiting, diarrhea (GLP-1R agonists)

Not applicable to native GLP-1 due to non-therapeutic use.

GLP-1 resistance

—

High glucose-induced PKCβ overexpression may reduce GLP-1 responsiveness in endothelial cellsPujadas 2016

Absolute Contraindications

GHRP-2

·Active malignancy
·Pregnancy / breastfeeding

GLP-1 (7-37)

—

Relative Contraindications

GHRP-2

·Untreated diabetes

GLP-1 (7-37)

—

05Administration Protocol

Parameter

GHRP-2

GLP-1 (7-37)

1. Reconstitution

Add 2 mL bacteriostatic water to 5 mg vial → 2.5 mg/mL.

Native GLP-1(7-37) is not formulated for therapeutic use. Administered IV or SC in experimental protocols to study GLP-1R pharmacology and as reference standard for analogue development.

2. Injection site

SQ — abdomen or thigh. Rotate sites.

Lyophilised peptide stored at -20°C or below. Reconstituted solutions should be prepared fresh and used immediately due to rapid degradation.

3. Timing

Pre-sleep + fasted preferred.

For therapeutic GLP-1R activation, use FDA-approved long-acting analogues: semaglutide (once weekly), liraglutide (once daily), dulaglutide (once weekly), or exenatide (twice daily or once weekly).

4. Storage

Lyophilised: room temp, light-protected. Reconstituted: refrigerate ≤30 days.

—

5. Needle

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 1990 Teichman 2006

GLP-1 (7-37)

— no documented stacks