Ipamorelin is a synthetic pentapeptide amide, Aib-His-D-2-Nal-D-Phe-Lys-NH2, developed under the research code NNC 26-0161. Three of its building blocks are non-proteinogenic: α-aminoisobutyric acid (Aib) at the N-terminus, D-2-naphthylalanine at position 3 and D-phenylalanine at position 4. It was identified in a medicinal-chemistry series in which the central Ala-Trp dipeptide of the earlier growth-hormone-releasing peptide scaffold was removed.

Reported molecular pharmacology describes it as a selective agonist at the ghrelin receptor GHSR-1a. In primary rat pituitary cell assays its reported potency and intrinsic activity resemble those of GHRP-6, and antagonist profiling has been used to attribute its action to the GHRP-like receptor rather than the GHRH receptor.

Cited in GPCR pharmacology, receptor selectivity and binding assays, primary pituitary cell culture and peptide medicinal chemistry. Supplied as a lyophilized solid.

Research use only. This material is sold for in-vitro laboratory research and development purposes exclusively. It is not a drug, food, or dietary supplement, has not been evaluated by the FDA, and must not be used in humans or animals.