Beta Melanocyte Stimulating Hormone - Beta Melanocyte Stimulating Hormone is a 22 amino acid peptide produced from the prohormone, Proopiomelanocorticotropin. One of the fragments of Proopiomelanocorticotropin is b-Lipotropin which is further fragmented to form gamma Lipotropin and beta Endorphin. The gamma Lipotropin is then cleaved to form beta MSH. The major biological property of beta MSH is hyperpigmentation. Beta MSH is the major melanocortin in humans. Beta-Melanocyte Stimulating hormone has been found in high levels in patients with Cushings disease, ectopic ACTH producing tumors and also in some non-endocrine tumors.