Ipamorelin

Starting with the compound NNC 26-0194 [3-(4-imidazolyl) propionyl-D-Phe-Ala-Trp-D-Phe (CH2NH) Lys-ol], Novo Nordisk researchers have developed NNC 26-0161 (ipamorelin)1. Ipamorelin is able to induce a massive release of GH, being active by the intravenous (i.v.), intra-muscular, subcutaneous and oral routes and, interestingly, also by the iontophoresis transdermal route2.

Ipamorelin exhibits linear pharmokinetics.

This GH-releasing peptide has a terminal half-life of at least 2 hours with a systemic clearance of .078 L/h/kg and a steady-state volume distribution of .22 L/kg in a typical subject. A large molecule such as a peptide is primarily localized in the central compartment and thus a small volume distribution is expected.3


GHRP-2 in short prepubertal children also produced a small volume distribution (0.32 L/kg) and a half-life of 1.5 hours. 4

Ipamorelin has a 25% longer half-life then GHRP-2.

Ipamorelin’s effect on GH

GH concentrations rise to a sharp peak around .67 hours and decline to very low concentrations in all dosing levels by hour 6. The GH peak concentration levels occur after Ipamorelin peak concentration levels. The plasma Ipamorelin concentration level persisted for longer duration then GH plasma concentration levels and continued to exert an effect on smaller pulses.