Ipamorelin
Available as ORIN
Molecular profile
| Sequence |
Aib-His-D-2-Nal-D-Phe-Lys-NH2 |
| Formula |
C38H49N9O5 |
| Class |
Selective growth hormone secretagogue |
A selective growth hormone secretagogue (ghrelin / GHS-receptor agonist), a synthetic pentapeptide containing two non-standard residues, 2-aminoisobutyric acid and D-2-naphthylalanine, with a C-terminal amide. Studied for growth hormone release via a GHRP-like receptor without significant change in ACTH, cortisol, or prolactin.
Selectivity as a secretagogue
The 1998 founding study reported that ipamorelin released growth hormone from primary rat pituitary cells with potency and efficacy comparable to GHRP-6, acting via a GHRP-like receptor, and that unlike some earlier secretagogues it did so without raising ACTH or cortisol.
Skeletal research in rats
A 1999 study injected ipamorelin at 18, 90, and 450 micrograms per day into adult female rats for 15 days and reported a dose-dependent increase in longitudinal bone growth rate at the proximal tibia (42 to 52 micrometres per day), with no change in total IGF-I.
Gastrointestinal motility
A 2012 study in a rodent model of postoperative ileus reported that ipamorelin, a ghrelin mimetic, accelerated gastric emptying through a GHS-receptor-mediated cholinergic mechanism.
Peer-reviewed references
-
Raun K, Hansen BS, Johansen NL, Thogersen H, Madsen K, Ankersen M, Andersen PH. Ipamorelin, the first selective growth hormone secretagogue. Eur J Endocrinol. 1998;139(5):552-561. doi.org/10.1530/eje.0.1390552
-
Johansen PB, Nowak J, Skjaerbaek C, Flyvbjerg A, Andreassen TT, Wilken M, Orskov H. Ipamorelin, a new growth-hormone-releasing peptide, induces longitudinal bone growth in rats. Growth Horm IGF Res. 1999;9(2):106-113. doi.org/10.1054/ghir.1999.9998
-
Greenwood-Van Meerveld B, Tyler K, Mohammadi E, Pietra C. Efficacy of ipamorelin, a ghrelin mimetic, on gastric dysmotility in a rodent model of postoperative ileus. J Exp Pharmacol. 2012;4:149-155. doi.org/10.2147/JEP.S35396