Difference Between GHRP 2 and GHRP 6 Peptides Comparison 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 What Is Ipamorelin and How Does It Compare vs HGH and Peptides Ghrelin: Trends in Endocrinology & Metabolism Can Ipamorelin cause erectile dysfunction? Ghrelin Stimulates Appetite, Imagination of Food, GH, ACTH, and Cortisol, but does not Affect Leptin in Normal Controls Neuropsychopharmacology