GHRP-6 (Growth Hormone Releasing Peptide-6) is a synthetic hexapeptide developed by Bowers et al. in the 1980s. It was one of the first synthetic growth hormone secretagogues and played a decisive role in the discovery of the ghrelin receptor (GHSR-1a).
The realisation that GHRP-6 acted through a previously unknown receptor distinct from the GHRH receptor led to the discovery of ghrelin in 1999 — a gastric hormone that proved to be the natural endogenous ligand of GHSR-1a. This finding is regarded as one of the most significant contributions of peptide research to endocrinology.
GHRP-6 binds with high affinity to GHSR-1a in the pituitary gland and hypothalamus. Receptor activation leads to mobilisation of intracellular calcium, triggering pulsatile GH release from somatotropic cells of the pituitary.
Compared to more selective peptides such as Ipamorelin, GHRP-6 also stimulates cortisol and prolactin in measurable amounts alongside GH secretion. This makes it an interesting research tool when investigating the selectivity profile of GHSR-1a agonists.
In fundamental research, GHRP-6 is used to study the mechanisms of pulsatile GH secretion and the physiological role of ghrelin in energy regulation and appetite control. Studien Peptide offers GHRP-6 as a high-purity lyophilised peptide for authorised research laboratories.
What do we know in 2026 about the lipolytic mechanisms of HGH Fragment 176-191 (AOD9604)? Current research data on beta-3-AR and fat breakdown.
Tesamorelin has been FDA-approved since 2010. What has research learned since then? New findings on lipodystrophy, myosteatosis and MASLD.
TB-500 and BPC-157 are frequently used in combination in research laboratories. What science knows about their complementary mechanisms.