Ipamorelin

Ipamorelin (NNC 26-0161) is a synthetic five-amino-acid peptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) developed by Novo Nordisk in the 1990s. It acts on the ghrelin receptor, the same target as GHRP-6. In rat pituitary cells and in rats it released growth hormone (GH) about as strongly as GHRP-6, and in pigs it did not raise ACTH or cortisol, even at very high amounts, unlike GHRP-6 and GHRP-2 (Raun et al., Eur J Endocrinol 1998). This selectivity was shown in pigs; published human data on other hormones are limited. In healthy men, a dose-escalation study found a single short burst of GH after each dose and a half-life of about two hours (Gobburu et al., Pharm Res 1999). Because ghrelin-receptor stimulation affects gut movement, ipamorelin was studied for postoperative ileus (slow return of gut function after surgery). In rats after abdominal surgery it shortened the time to first bowel movement, but a phase 2 randomised, double-blind, placebo-controlled trial in 114 adults after bowel resection found no clear difference from placebo in time to tolerating a solid meal, or in secondary measures (Beck et al., Int J Colorectal Dis 2014). It was well tolerated in that trial. There are no published long-term human safety data. Supplied for laboratory research use only.