Normal Physiology of ACTH and GH Release in the Hypothalamus and Anterior Pituitary in Man Endotext NCBI Bookshelf 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 Endocrine Diseases Springer Nature Link Changes in pituitary function with ageing and implications for patient care Nature Reviews Endocrinology Normal Physiology of ACTH and GH Release in the Hypothalamus and Anterior Pituitary in Man Endotext NCBI Bookshelf 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