Melanotan II | 20 | 3ml

Melanotan II (MT‑II) is a synthetic cyclic heptapeptide analogue of α‑melanocyte‑stimulating hormone (α‑MSH), developed for controlled laboratory investigation of the melanocortin signalling system. Its sequence — Ac‑Nle‑cyclo[Asp‑His‑D‑Phe‑Arg‑Trp‑Lys]‑NH₂ — incorporates a norleucine substitution, a D‑phenylalanine substitution, and a lactam bridge that cyclises the molecule, conferring markedly greater stability and resistance to enzymatic degradation than the native linear hormone. These structural features make MT‑II a robust reference compound for receptor‑pharmacology and structure–activity research.\n\nIn biochemical and cellular research systems, MT‑II acts as a broad, non‑selective agonist across the melanocortin receptor family — MC1R, MC3R, MC4R and MC5R — with negligible activity at MC2R. This wide receptor coverage makes it a foundational tool for probing melanocortin‑receptor binding, G‑protein‑coupled cAMP signalling, and downstream transcriptional responses, as well as for comparative selectivity studies against more receptor‑selective analogues. The molecular responses observed vary according to receptor subtype, peptide concentration, exposure time, cell model, and overall study design, and MT‑II is employed to characterise melanocortin‑receptor signalling rather than to infer defined biological or physiological effects.