Research Peptide · For laboratory research use only
Also known as NNC 26-0161
Ipamorelin (NNC 26-0161) is a synthetic pentapeptide growth hormone secretagogue, Aib-His-D-2Nal-D-Phe-Lys-NH2. It emerged from a chemistry programme based on growth hormone-releasing peptide-1 (GHRP-1) and was identified within a series of compounds lacking the central Ala-Trp dipeptide of GHRP-11. It is an agonist of the ghrelin receptor (growth hormone secretagogue receptor)6.
Published work includes in vitro and in vivo pharmacology in rats and swine, pharmacokinetics in rats, rodent studies of bone growth, bone mineral content and adiposity, a rodent model of postoperative ileus, and a registered phase 2 trial1,2,3,4,5,6,7.
As described in the research literature
As described in the research literature, ipamorelin released growth hormone from primary rat pituitary cells with potency and efficacy similar to GHRP-6, and profiling with GHRP and GHRH antagonists indicated that it acts through a GHRP-like receptor1. In swine it did not change FSH, LH, prolactin or TSH and, unlike GHRP-6 and GHRP-2, did not raise ACTH or cortisol beyond the levels seen with GHRH, which led the authors to describe it as the first selective growth hormone secretagogue1.
Not every effect studied runs through growth hormone. In GH-deficient lit/lit mice as well as GH-intact mice, ipamorelin increased fat pad weights relative to body weight, and secretagogue treatment raised serum leptin and food intake, which the authors interpreted as GH-independent effects5. In a rat model of postoperative ileus, its activity as a ghrelin receptor agonist was examined for effects on gastrointestinal transit6.
What published studies have examined
Growth hormone release was measured in primary rat pituitary cells, anaesthetised rats and conscious swine, and the effects on ACTH, cortisol and other pituitary hormones were compared with GHRP-6 and GHRP-21.
Sources [1]
Plasma clearance, routes of excretion, metabolic stability and absorption in male rats were compared with GHRP-2, GHRP-6 and two related peptides2.
Sources [2]
Longitudinal bone growth rate in the proximal tibia was measured by tetracycline labelling in adult female rats3, and bone mineral content was followed by DXA and pQCT in young adult female rats4. Fat mass and serum leptin were compared in GH-deficient and GH-intact mice5.
A rat model of postoperative ileus examined time to first bowel movement, faecal pellet output, food intake and body weight6. A multicentre, randomised, double-blind, placebo-controlled phase 2 trial in patients undergoing bowel resection was designed with time to tolerance of a standardised solid meal as its key efficacy endpoint (NCT00672074)7.
Ipamorelin, the first selective growth hormone secretagogue.
Raun K, Hansen BS, Johansen NL, et al. European Journal of Endocrinology, 1998.
Pharmacokinetic evaluation of ipamorelin and other peptidyl growth hormone secretagogues with emphasis on nasal absorption.
Johansen PB, Hansen KT, Andersen JV, et al. Xenobiotica, 1998.
Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats.
Johansen PB, Nowak J, Skjaerbaek C, et al. Growth Hormone & IGF Research, 1999.
The GH secretagogues ipamorelin and GH-releasing peptide-6 increase bone mineral content in adult female rats.
Svensson J, Lall S, Dickson SL, et al. The Journal of Endocrinology, 2000.
Growth hormone (GH)-independent stimulation of adiposity by GH secretagogues.
Lall S, Tung LY, Ohlsson C, et al. Biochemical and Biophysical Research Communications, 2001.
Efficacy of ipamorelin, a novel ghrelin mimetic, in a rodent model of postoperative ileus.
Venkova K, Mann W, Nelson R, et al. The Journal of Pharmacology and Experimental Therapeutics, 2009.
Prospective, randomized, controlled, proof-of-concept study of the Ghrelin mimetic ipamorelin for the management of postoperative ileus in bowel resection patients.
Beck DE, Sweeney WB, McCarter MD International Journal of Colorectal Disease, 2014.
This page is provided for research and educational reference only. It does not constitute medical advice, dosing guidance, or a recommendation for use. All compounds are strictly for laboratory and in-vitro research purposes.