The N-terminal peptide/fragment of proopiomelanocortin (NPP; N-POMC) also known as pro-γ-MSH is a naturally-occurring endogenous metabolite of the polypeptide proopiomelanocortin (POMC).N-POMC is also a precursor for γ1-MSH γ2-MSH and γ3-MSH and can form them through proteolyic cleavage.