Schematic representation of prolactin signaling pathway in the Download Scientific Diagram 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 Reproductive Endocrinology Prolactin Disorders: Causes, Symptoms, and Treatment Options Prolactin Relationship with Fertility and In Vitro Fertilization OutcomesA Review of the Literature