Ipamorelin (INN) (developmental code name NNC 26-0161) is a peptide selective agonist of the ghrelin/growth hormone secretagogue receptor (GHS) and a growth hormone secretagogue.

[4] Ipamorelin significantly increases plasma growth hormone (GH) levels in both animals and humans.

[1][3][5] In addition, ipamorelin stimulates body weight gain in animals.

[3] However, unlike pralmorelin (GHRP-2) and GHRP-6, but similarly to growth hormone-releasing hormone (GHRH), ipamorelin does not stimulate the secretion of adrenocorticotropic hormone (ACTH), or cortisol, and is highly selective for inducing the secretion only of GH.

[3] Ipamorelin was originally developed by Novo Nordisk, and was investigated in phase II clinical trials by Helsinn Therapeutics for the treatment of postoperative ileus, but was discontinued due to lack of efficacy.