Melanotan II

Melanotan-II is a synthetic cyclic heptapeptide analog of α-melanocyte-stimulating hormone (α-MSH), engineered with a lactam bridge between residues to lock the bioactive conformation and confer enhanced metabolic stability relative to the native linear hormone. The peer-reviewed literature catalogs Melanotan-II as a non-selective melanocortin-receptor agonist and a research tool used in studies of MC1R, MC3R, MC4R, and MC5R receptor pharmacology. Investigators have characterized the molecule across in-vitro receptor-binding assays and in-cell signaling investigations. Its molecular identity is fixed by sequence and structural confirmation against PubChem CID 92432, empirical formula C50H69N15O9, with CAS Registry Number 121062-08-6. Supplied for laboratory characterization, in-vitro receptor-binding work, and in-cell signaling studies only. For research use only; not for human consumption, cosmetic application, medical use, or veterinary application.

Melanotan-II is a cyclic heptapeptide whose lactam bridge between residues 5 and 10 (Asp-D-Phe-Arg-Trp-Lys cycle plus N- and C-terminal capping) constrains the molecule into a conformation that mimics the receptor-binding geometry of α-MSH. The cyclic architecture confers proteolytic resistance and extended plasma residence relative to the linear native hormone, properties that have anchored its use as a research material across melanocortin-receptor pharmacology investigations. Pharmacokinetic descriptors documented in published animal-model investigations include moderate plasma residence under standard parenteral paradigms. Interaction profile in the literature spans non-selective agonism across MC1R, MC3R, MC4R, and MC5R, with downstream cAMP signaling activation documented at each receptor subtype. All activity descriptors here are framed as documented in published work. Structural confirmation is established by mass spectrometry and HPLC-validated purity on each Certificate of Analysis.

Experimental domains documented in the published literature include melanocortin-receptor binding-affinity assays across MC1R / MC3R / MC4R / MC5R subtypes, structure-activity studies probing the role of the lactam bridge in receptor engagement, in-vitro melanocyte signaling investigations, comparative work alongside MTII analogs such as Bremelanotide (PT-141), and central-melanocortin-pathway research in animal-model paradigms. Investigators have also characterized Melanotan-II in screening assays for melanocortin-selective ligand discovery. Use in laboratory research extends to mechanism-elucidation paradigms where the molecule serves as a non-selective melanocortin agonist for parsing receptor-subtype contributions to downstream signaling. The reference standard is supplied for these and equivalent in-vitro experimental contexts only, with no associated guidance for human, cosmetic, clinical, or veterinary application. Researchers should consult primary literature for context-specific protocols.

Each lot is characterized by reverse-phase HPLC for chromatographic purity and by mass spectrometry for molecular-ion confirmation against the C50H69N15O9 empirical formula. Purity is reported as an HPLC-area percentage on the Certificate of Analysis distributed with every lot, alongside the molecular-weight match within instrument tolerance. Peptide content where applicable is determined by amino-acid analysis or nitrogen-content assay following the analytical method specified on the COA. Residual solvent and water content are reported categorically when these parameters are part of the lot's release specification. The COA records the lot identifier, manufacturing date, and analytical method versions used, providing a traceable provenance chain from synthesis through release. Researchers requiring batch-level analytical detail should reference the COA distributed with the supplied material.

For laboratory storage, the lyophilized reference standard should be held at −20°C in its sealed, light-protected container until ready for analytical use. Allow vials to equilibrate to ambient temperature before opening to avoid moisture condensation on the lyophile. Reconstitution for in-vitro experimental use is typically performed in bacteriostatic water or a researcher-selected buffer compatible with the downstream assay; once reconstituted, store the working solution at 2–8°C and characterize stability in the relevant buffer prior to extended storage. Avoid repeated freeze-thaw cycles of reconstituted material — single-use aliquots are preferred for experiments where peptide integrity is assay-critical. These handling parameters reflect general best-practice for lyophilized peptide reference standards and do not constitute preparation guidance for human, cosmetic, or veterinary application.