Ipamorelin is a synthetic pentapeptide and selective agonist of the ghrelin receptor (GHS-R1a), designed to stimulate pituitary GH release with a high degree of selectivity and a clean hormonal profile. Unlike older GHRPs such as GHRP-6, ipamorelin does not significantly elevate cortisol, prolactin, or ACTH at research doses, making it one of the most selective GH secretagogues studied to date. It produces dose-dependent GH pulses and is commonly combined with GHRH analogues such as CJC-1295 to amplify the GH response through complementary receptor pathways. Its favorable selectivity profile has made it a benchmark compound in GH research.