Melanotan 2 is a conformationally constrained analog of alpha-melanocyte-stimulating hormone, and one of the most widely used reference ligands in melanocortin receptor research.

What Is Melanotan 2?

Alpha-melanocyte-stimulating hormone is a 13-amino-acid peptide acting across the melanocortin receptor family. Melanotan 2 is a synthetic analog shortened to seven amino acids and cyclised through a lactam bridge between lysine and aspartate residues.

The cyclisation is the key modification. Constraining the peptide into a fixed conformation both increases resistance to enzymatic degradation and locks the molecule into a shape favourable for receptor binding, producing substantially greater potency than the linear native peptide.

How Researchers Understand Its Mechanism

There are five melanocortin receptor subtypes, MC1R through MC5R, all G protein-coupled receptors signaling principally through cyclic AMP. They differ in tissue distribution: MC1R is expressed mainly on melanocytes, MC2R in the adrenal cortex, MC3R and MC4R mainly in the central nervous system, and MC5R in exocrine glands.

Melanotan 2 is a non-selective agonist, engaging MC1R, MC3R, MC4R and MC5R. This non-selectivity is precisely why it is valuable as a research tool: it serves as a broad-spectrum reference ligand against which more selective compounds are characterised.

Its relationship to PT-141 is worth noting. PT-141, or bremelanotide, is a metabolite of Melanotan 2 differing by the absence of the C-terminal amide group, and shows relative preference for MC4R. The pair allows researchers to examine how a small structural change shifts receptor selectivity.

Areas of Scientific Investigation

Applications include melanocortin receptor selectivity profiling, cyclic peptide structure-activity relationship studies, cyclic AMP signaling assays, melanocyte cell-culture models, and comparative work with Melanotan 1, which is MC1R-selective.

Why Purity and Verification Matter

Reproducibility in peptide research depends on knowing exactly what is in the vial. Sequence-related impurities, truncated fragments and residual synthesis reagents can all influence experimental outcomes, and two preparations nominally of the same compound can behave differently if purity differs. Independent HPLC and mass spectrometry testing establishes both identity and purity, which is why third-party verification is standard practice for research-grade material. All compounds referenced here are supplied as lyophilized powder at 99%+ purity with independent verification.

Summary

Melanotan 2 is a cyclic lactam analog of alpha-MSH with non-selective agonist activity across MC1R, MC3R, MC4R and MC5R. Its conformational constraint confers stability and potency, and its breadth makes it a standard comparator in melanocortin receptor research. It is intended strictly for laboratory research.

Related Research Peptides

Melanotan 2 10mg · Melanotan 1 10mg · PT-141 10mg · KPV 10mg

For laboratory and research use only. Not for human or veterinary use, and not for diagnostic or therapeutic purposes.