Melanotan II

Molecular Mechanism

Melanotan II (MT-II) is a cyclic heptapeptide designed as a synthetic analog of alpha-melanotropin (alpha-MSH) at the University of Arizona laboratory. The cyclic lactam structure between Asp and Lys residues confers higher proteolytic stability than linear alpha-MSH. MT-II acts as a non-selective melanocortin receptor agonist at MC1R, MC3R, MC4R, and MC5R, without activity at MC2R.

In in vitro studies, MC1R activation stimulates the cAMP/PKA pathway in melanocytes, leading to CREB phosphorylation and transcription of melanogenesis-related genes (tyrosinase, TRP-1, TRP-2). Concurrent affinity for MC3R and MC4R in the central nervous system modulates neuroendocrine pathways studied in the context of energy homeostasis regulation.

Melanotan II vs PT-141

Melanotan II and PT-141 are structurally related melanocortin peptides. PT-141 (Bremelanotide) is the active metabolite of Melanotan II, formed by removal of the C-terminal amide group.

The key structural difference is the presence of an amide group at the C-terminus of Melanotan II (-NH₂), while PT-141 has a free carboxyl group (-OH). This modification affects the receptor affinity profile — Melanotan II shows stronger MC1R/melanogenesis pathway activation, while PT-141 is studied primarily in the context of MC4R pathways.

Stability and Storage

In lyophilized form, store Melanotan II at -20°C for long-term stability (at least 24 months). After reconstitution in sterile water, the solution remains stable for up to 30 days at 2-8°C. The cyclic lactam structure and absence of methionine residues in the sequence minimize the risk of oxidation and proteolytic degradation.

Related Research Materials

Melanotan II is structurally related to PT-141 (Bremelanotide) — its active metabolite differing in the C-terminal group. Both peptides belong to the family of synthetic alpha-MSH analogs with cyclic lactam structure.

Intended Use

This product is a chemical raw material intended exclusively for in vitro research, scientific, and analytical applications. It is not intended for human or veterinary use, including for diagnostic, therapeutic, prophylactic, or nutritional purposes.

Handling

• Work in laboratory conditions consistent with Good Laboratory Practice (GLP) principles.
• Use appropriate personal protective equipment: nitrile gloves, safety goggles, lab coat.
• Avoid inhalation of dust and contact with skin or mucous membranes.
• Work in a well-ventilated area.

Regulatory Classification

This product is not classified as a hazardous substance under CLP Regulation (EC) No 1272/2008. It is offered as a chemical reagent within the framework of applicable European Union chemical substances regulations (REACH, CLP). It does not constitute a medicinal product, dietary supplement, medical device, or cosmetic within the meaning of applicable laws.

Disposal

Unused material should be disposed of in accordance with local regulations on chemical waste. Under laboratory conditions: neutralize and dispose with laboratory waste streams. Do not discharge into sewage systems.

Regulatory Information

This product is offered in accordance with applicable European Union regulations on chemical substances (REACH, CLP) and Polish law governing the trade of chemical reagents and research materials. Full terms of sale and product classification are set out in the Terms of Service.

By placing an order, the Customer confirms having read the above information and accepts the provisions of the Terms.

Product-Specific Notes

Melanotan II is a non-selective agonist of melanocortin receptors (MC1R/MC3R/MC4R/MC5R). Research literature has documented adverse events associated with melanocortin activation, including effects on blood pressure, energy homeostasis, and melanocyte activity. Handling requires particular care in accordance with the internal laboratory protocol. Research substance — not intended for use in humans or animals.

Safety Contact

For questions regarding handling or regulatory information: [email protected].