Function
While CJC-1295 is used in research to chronically elevate endogenous growth hormone and IGF-1 levels, enabling studies of body composition, metabolic, and anti-aging effects of prolonged GH exposure10, Melanotan I is approved in some regions for prevention of phototoxicity in erythropoietic protoporphyria and is studied as a skin-darkening, photoprotective peptide3444.
Mechanism
While CJC-1295 works as a tetrasubstituted 29-amino-acid analog of GHRH(1–29) that acts as a potent agonist at the GHRH receptor and, in its DAC form, covalently binds serum albumin to extend half-life from minutes to days, resulting in sustained pulsatile GH and IGF-1 increase1082, Melanotan I is a linear 13-amino-acid analog of α-MSH (afamelanotide) that selectively activates MC1R on melanocytes, increasing eumelanin synthesis and providing photoprotection3444.
Length and Sequence
CJC-1295 is 29 amino acids long, whereas Melanotan I is shorter as it has a length of 13 amino acids. CJC-1295 is made up of a sequence of Tyrosine, Alanine, Aspartic acid, Alanine, Isoleucine, Phenylalanine, Threonine, Glutamine, Serine, Tyrosine, Arginine, Lysine, Valine, Leucine, Alanine, Glutamine, Leucine, Serine, Alanine, Arginine, Lysine, Leucine, Leucine, Glutamine, Aspartic acid, Isoleucine, Leucine, Serine, Arginine. Melanotan I is made up of a sequence of Serine, Tyrosine, Serine, Nle, Glutamic acid, Histidine, Phenylalanine, Arginine, Tryptophan, Glycine, Lysine, Proline, Valine.