What the label states, the lot delivers — net peptide mass, not gross powder weight, purity reported as measured rather than rounded up, and a Certificate of Analysis for every lot.
Net peptide mass, not powder weight; purity as measured, not rounded up; a COA per lot.
Net peptide + purity not rounded up. COA per lot.
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Cyclic α-MSH analog · melanocortin agonist
Overview
Melanotan II (MT-II) is a synthetic cyclic heptapeptide analogue of α-melanocyte-stimulating hormone (α-MSH), Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2. The lactam-bridged ring and the D-phenylalanine substitution lock the pharmacophore into a protease-resistant, high-affinity conformation, making MT-II a potent non-selective melanocortin-receptor agonist studied for melanogenesis (MC1R) in pigmentation research and for MC4R-mediated effects in appetite and sexual-function models. It is the research-reference parent compound to the linear analogue afamelanotide. Vialdyne releases lyophilised Melanotan II acetate at ≥99.0% HPLC main-peak, with a batch COA covering RP-HPLC purity, peptide-content assay, ESI-MS identity confirming the cyclic mass, water (Karl Fischer), counter-ion, residual solvents, and endotoxin. Because the activity depends on an intact lactam ring, the released-batch identity is confirmed by mass spec rather than retention time alone.
Applications & buyer fit
Cosmetic-peptide buyers fall into two groups: established beauty / med-aesthetic brands extending an existing line, and OEM clients building a private-label catalog from scratch. The first group usually wants active material plus stability data in their existing carrier matrix; the second usually wants a finished formulation under their label. Both need INCI naming verified, regulator-specific safety files (CPNP for EU, FDA OTC monograph for US where relevant), and packaging-compatibility data.
Sourced for
Buyer fit
Documentation that ships
Procurement note: INCI naming, SDS, and stability data in the chosen carrier ship with the active; finished-product safety remains the brand owner's responsibility.
Primary buyer fit: academic and contract research laboratories.
Specifications
Certificate of Analysis
Published released-batch COAs for Melanotan II, every lot HPLC-verified. These are previews — request the full high-resolution certificate for any lot.
Browse all published COAsRegulatory note
Research-use-only reference material; Melanotan II is not approved as a finished drug in the US or EU. Not for human or veterinary use. Buyers are responsible for verifying regulatory status in the destination market.
Selected literature
Frequently asked questions
Melanotan II is a cyclic, lactam-bridged heptapeptide and a non-selective melanocortin agonist (MC1R and MC4R, among others). Melanotan I (afamelanotide) is a linear α-MSH analogue that is more MC1R-selective and is an approved drug for erythropoietic protoporphyria in some markets. The cyclic ring in MT-II is the structural reason for its higher potency and broader receptor coverage; the released-batch COA confirms the cyclic mass by ESI-MS so the two analogues are not confused at receiving.
MT-II's activity depends on an intact lactam ring between the Asp and Lys side chains. A ring-opened (linear) impurity can co-elute closely on RP-HPLC but has a different mass and reduced activity, so Vialdyne confirms identity by ESI-MS against the theoretical cyclic mass (1024.18 g/mol) on every released lot, not by retention time alone. Peptide-content assay, counter-ion, water, residual solvents, and endotoxin complete the release file.
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