Prolactin ScienceDirect 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 Corticotrophin releasing hormone Hormones 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