A pentapeptide (Aib-His-D-2-Nal-D-Phe-Lys-NH2) and a ghrelin mimetic with growth hormone (GH) releasing activity. Ipamorelin mimics ghrelin and binds to the ghrelin receptor (or GH secretagogue receptor, GHSR) in the brain, thereby selectively stimulating the release of GH from the pituitary gland. This results in increased plasma GH levels, which would affect many biological processes. Besides its presence in the brain, GHSR can also be found in the gastrointestinal tract, heart, lung, liver, kidney, pancreas, adipose tissue and immune cells. Unlike other GH releasing peptides, ipamorelin only stimulates GH release in a manner very similar to that of growth hormone releasing hormone.