Ghrelin vs Ipamorelin

Must be acylated at Ser3 (by GOAT enzyme) for GHSR-1a binding. Receptor activation in the pituitary stimulates GH release; hypothalamic action via NPY/AgRP neurons increases appetite and reduces energy expenditure.

An endogenous 28-amino acid peptide hormone produced primarily by gastric oxyntic cells. Functions as both the primary hunger signal and a potent GH secretagogue. The natural ligand for the growth hormone secretagogue receptor (GHSR-1a).

Ipamorelin binds to the ghrelin receptor (GHSR-1a) and stimulates dose-dependent GH release with a clean hormonal profile. Unlike GHRP-6 or hexarelin, it does not significantly stimulate appetite-related pathways or cortisol secretion at standard research doses. This selectivity makes it a frequently studied peptide for protocols where hormonal side-effect profiles are a consideration.

Ipamorelin is a selective growth hormone secretagogue and ghrelin receptor agonist. It stimulates pulsatile GH release from the anterior pituitary with high selectivity — producing minimal effect on cortisol, prolactin, or ACTH compared to earlier GHRPs. It is commonly researched for its role in supporting body composition, recovery, and lean mass maintenance.