GHRP-6

GHRP-6 is a synthetic hexapeptide (His-D-Trp-Ala-Trp-D-Phe-Lys-NH2) and the prototypical growth-hormone-releasing peptide. It was among the earliest GH secretagogues discovered (by Cyril Bowers and colleagues) and acts as an agonist at the growth-hormone secretagogue receptor type 1a (GHS-R1a), the same receptor activated by the natural hormone ghrelin. Like ghrelin, it prompts the pituitary to release growth hormone in pulses while also strongly stimulating appetite - the feature most consistently reported with GHRP-6, generally more pronounced than with GHRP-2. The published evidence is concentrated in pharmacology rather than clinical outcomes. Human studies have characterized GHRP-6's pharmacokinetics and its dose-dependent capacity to release GH and increase food intake, while a substantial body of preclinical work in rodent and large-animal models reports cytoprotective and cardioprotective effects. There are no large controlled clinical efficacy trials and no regulatory approval of GHRP-6 as a therapeutic in any major jurisdiction. It is worth noting a common point of confusion: the [D-Lys3] analog of GHRP-6 is, by contrast, a widely used ghrelin-receptor antagonist in laboratory research and should not be conflated with GHRP-6 itself. GHRP-6 is prohibited in sport by WADA, and material sold online is labeled for research use only. This entry summarizes the published science and community-reported practice for reference only. It is not medical advice and does not endorse human use.