Corticotrophin releasing hormone Hormones Ipamorelin is a potent growth hormone releasing peptide that has some potential advantages over some of the others. Although peptides seem to be doled out like aspirin, keep in mind that these are Ipamorelin is a pentapeptide. Five amino acids. That's it. But three of those five don't exist in nature. The sequence: Aib His D 2 Nal D Phe Lys, with a C terminal amide. Position 1 is aminoisobutyric acid the Normal Physiology of ACTH and GH Release in the Hypothalamus and Anterior Pituitary in Man Endotext NCBI Bookshelf