Normal Physiology of ACTH and GH Release in the Hypothalamus and Anterior Pituitary in Man Endotext NCBI Bookshelf Therapeutic Peptides in Aesthetic, Metabolic and Endocrine Conditions: Effects, Safety, Clinical Applications, and Future Perspectives 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 Normal Physiology of ACTH and GH Release in the Hypothalamus and Anterior Pituitary in Man Endotext NCBI Bookshelf