MT2 (Melanotan II) is a synthetic analogue of alpha-melanocyte-stimulating hormone (α-MSH), a naturally occurring peptide hormone involved in regulating pigmentation and appetite via the melanocortin receptor system. Research on MT2 has centred on its activity at melanocortin receptors, particularly MC1R, which plays a central role in melanogenesis (the pigmentation pathway within melanocytes), and MC4R, which is implicated in central appetite and energy balance signalling within the hypothalamus. As a non-selective agonist across these receptor subtypes, MT2 has been used in research settings to probe melanocortin receptor pharmacology more broadly, including its downstream effects on cyclic AMP signalling and receptor desensitisation.