Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of GHRP-2 and GHRP-6 — mechanism, side effects, legal status, and pricing.
GHRP-2 (pralmorelin) is a synthetic hexapeptide ghrelin receptor agonist that stimulates pituitary growth hormone release. It is approved in Japan (Kaken Pharmaceutical, 2004) as a single-dose diagnostic agent for GH deficiency, but is NOT FDA-approved in the US and is research-only. Unlike ipamorelin, GHRP-2 is non-selective and modestly raises ACTH, cortisol, and prolactin.
GHRP-6 is a synthetic hexapeptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) growth hormone secretagogue and ghrelin receptor agonist. Developed by Bowers and Momany and first described in 1984, it was the first synthetic GHRP characterized and is defined by its pronounced appetite-stimulating effect — the strongest of any clinically studied GHRP. It has never been approved by the FDA or any regulatory agency and remains a research-only compound used off-label in the grey market.
GHRP-2
GHRP-6
Category
Legal Status
Mechanism
Half-life
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
GHRP-2
GHRP-6
COA corpus from Disclosed Labs — independently tested batches only.
GHRP-2
13
COAs
99.3%
Avg purity
6
Labs
GHRP-6
13
COAs
99.4%
Avg purity
4
Labs
GHRP-2 is approved in Japan (Kaken Pharmaceutical, 2004) as pralmorelin for single-dose diagnostic GH-stimulation testing; Chihara et al. (2007, PMID 17609397) validated a 100 mcg IV dose with a peak-GH <15 mcg/L cut-off against the insulin tolerance test. Arvat et al. (1997, PMID 9285939) showed GHRP-2 raises GH, prolactin, ACTH, and cortisol in healthy men, with hormonal effects similar to hexarelin. Laferrère et al. (2005, PMID 15699539) demonstrated that IV GHRP-2 significantly increases food intake in healthy men, consistent with its ghrelin-like activity. Pralmorelin review: Drugs R D 2004 (PMID 15230633). GHRP-2 is more potent than ipamorelin for raw GH output but is non-selective; grey-market anti-aging, muscle-gain, and performance use is not clinically validated in the US.
Key references
GHRP-6 was first characterized by Bowers, Momany, Reynolds, and Hong in Endocrinology (1984, PMID 6714155), establishing it as the first synthetic peptide to specifically release GH via a non-GHRH mechanism — a key tool in the later discovery of the ghrelin receptor. Ghigo et al. (European Journal of Endocrinology, 1997, PMID 9186261) reviewed the GHRP class and confirmed GH, ACTH/cortisol, and prolactin co-stimulation in humans. Berlanga et al. (Clinical Science, 2007, PMID 16989643) demonstrated ~78% infarct-mass reduction in a porcine myocardial infarction model via antioxidant mechanisms, and Berlanga-Acosta et al. (Clinical Medicine Insights: Cardiology, 2017, PMID 28469491) reviewed the cytoprotective GHRP literature across cardiac, neuronal, and hepatic tissues. GHRP-6 has never been approved for any clinical indication; its intense appetite stimulation and cortisol/prolactin co-release limit its clinical utility compared with ipamorelin.
GHRP-2 and GHRP-6 are both in the Performance category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Key references