Growth Hormone · Appetite · Endocrine
GHRP-6
Also known as: Growth Hormone Releasing Peptide-6, Histrelin (incorrect; unrelated), SKF-110679
The first widely studied synthetic hexapeptide growth hormone secretagogue and the original tool compound used to identify the GHSR-1a receptor, with notable appetite-stimulating effects.
Sign in to add to watchlistEvidence strength
Strength of human clinical evidence — A (strongest) to D (mostly preclinical). This reflects research maturity, not safety or suitability.
Vial Theory provides educational research summaries only. Content is not medical advice, diagnosis, treatment, dosing guidance, or individualized suitability screening. Regulatory status can change over time and varies by jurisdiction.
Key Takeaways
- ›GHRP-6 was the first widely studied growth hormone releasing peptide and a key research tool in discovering the ghrelin receptor.
- ›It triggers growth-hormone release and strongly stimulates appetite.
- ›It raises cortisol and prolactin more than newer secretagogues, and its effect fades with repeated use.
- ›It is not approved for any therapeutic use and is on the WADA prohibited list.
- ›Body-composition claims exceed the evidence. Speak with a licensed healthcare professional.
What It Is
GHRP-6 is a synthetic hexapeptide developed in the 1980s by Cyril Bowers and colleagues at Tulane University, in collaboration with what was then SmithKline Beckman. It was the first widely studied member of the growth hormone releasing peptide class and historically the tool compound that led to the identification of an unknown receptor target, eventually characterized as the growth hormone secretagogue receptor (GHSR-1a) and recognized as the endogenous receptor for ghrelin.
The sequence (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) is structurally related to other GHRPs but produces a distinctive pharmacological profile including pronounced appetite stimulation. Its development pre-dated the identification of ghrelin itself by more than a decade, and the eventual recognition that GHRPs were acting at the ghrelin receptor reframed the understanding of both the GHRP class and endogenous appetite-regulation biology.
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Disclaimer: This content is for educational and research purposes only and is not medical advice. Always consult a licensed healthcare professional before making health-related decisions.