For laboratory research use only.
Melanotan I and Melanotan II are synthetic melanocortin receptor agonist peptides. They share a research neighborhood with alpha-MSH, KPV, and PT-141/bremelanotide, but each name tracks a different structure and evidence trail.
Receptor family
Melanocortin receptors (MC1R–MC5R in canonical descriptions) link pigmentation biology, energy-balance models, and other peptide pharmacology themes. Melanotan I (afamelanotide in some pharmaceutical contexts) and Melanotan II are engineered agonists with different selectivity emphases; methods should name both the analog and the receptor hypothesis under test.
Experimental snapshots
Melanotan-II microinjected into the nucleus accumbens decreased appetitive behavior in a reported rodent study, illustrating CNS melanocortin effects beyond skin pigmentation models (MT-II nucleus accumbens study). Medicinal-chemistry work has used Melanotan-II as a starting point for designing functionally selective human melanocortin receptor agonists (CLIPSing Melanotan-II). Other model papers report cognitive or metabolic-adjacent endpoints after Melanotan-II in high-fat-diet contexts (MT-II and HF-diet memory model).
Related ligands without synonym collapse
PT-141/bremelanotide shares chemistry history with Melanotan II but is a distinct development entity. KPV is a three-residue alpha-MSH fragment used mainly in inflammatory-signaling models. Neither replaces Melanotan I or II when a protocol names those analogs. Popular “tanning peptide” narratives are not laboratory methods and are not reproduced here.
Limits
Receptor-subtype papers and animal behavioral studies support research interest. They do not establish consumer use cases for research-catalog materials.
Sources
- Melanocortin receptor agonist melanotan-II microinjected in the nucleus accumbens decreases appetitive and consumptive responding for food. (Neuropeptides, 2022, PMID 36155088)
- CLIPSing Melanotan-II to Discover Multiple Functionally Selective hMCR Agonists. (J Med Chem, 2022, PMID 35188390)
- Melanotan-II reverses memory impairment induced by a short-term HF diet. (Biomed Pharmacother, 2023, PMID 37478579)