Neuropeptide ACTH (adenocorticotropin) amino acids (1-39), Cat AS-20610, is the natural cleavage product from POMC (proopimelanocortin) processing; however, the first 24-amino acid sequence from the carboxyl end, ACTH (1-24) has full biological activity of the (1-39) peptide. Both ACTH (1-24) and (1-39) possess neurotropic activity.