Melanotan 2 (also referred to as Melanotan II) is a synthetically produced variant of a peptide hormone naturally produced in the body that stimulates melanogenesis, a process responsible for pigmentation of the skin. This peptide hormone, called alpha-Melanocyte stimulating hormone or MSH, activates certain melanocortin receptors in the process of exerting its effects. Indeed, MSH also exerts potent influence over lipid metabolism, appetite, and sexual libido via these melanocortin receptors. As a result, Melanotan 2 has been shown in studies to exhibit appetite suppressant, lipolytic, and libido-enhancing effects in addition to promoting skin tanning. Melanotan 2 has been researched extensively for use in protecting against the harmful effects of ultraviolet radiation from sunlight due to its melanogenesis-stimulating properties.