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Melanotan II Research Overview

An overview of Melanotan II, a synthetic melanocortin receptor agonist, and its role in pigmentation and metabolic research.

Scientific background / literature overview only. Discussion of published research does not describe the intended use of Novex Peptide products.

Novex Peptide Research Team1 August 2026 7 min read

Melanotan II melanocortin pigmentation α-MSH melanogenesis

Introduction

Melanotan II (MT-II) is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH). It was developed at the University of Arizona in the 1990s and has been studied for its effects on melanogenesis, appetite regulation, and sexual function in animal models.

Mechanism of Action

Melanocortin Receptor Agonism

Melanotan II acts as an agonist at multiple melanocortin receptors:

**MC1R:** Involved in melanogenesis and skin pigmentation

**MC3R:** Involved in energy homeostasis and appetite regulation

**MC4R:** Involved in appetite regulation and sexual function

**MC5R:** Involved in exocrine gland function

Melanogenesis Stimulation

Through MC1R activation, Melanotan II stimulates melanocytes to produce eumelanin, resulting in increased skin pigmentation in animal models.

Current Research

Pigmentation Research

Animal studies have investigated Melanotan II's effects on melanogenesis, skin pigmentation, and UV protection.

Metabolic Research

Studies have explored Melanotan II's effects on appetite suppression, energy expenditure, and weight regulation through MC3R and MC4R activation.

Sexual Function Research

Animal studies have investigated Melanotan II's effects on sexual arousal and erectile function through MC4R-mediated pathways in the central nervous system.

Chemical Properties

**Sequence:** Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2 (7 amino acids, cyclic)

**Molecular formula:** C50H69N15O9

**Molecular weight:** 1,024.16 g/mol

**Modification:** N-terminal acetylation, C-terminal amidation, lactam bridge (cyclic)

Storage Considerations

Store lyophilised Melanotan II at -20°C.

Protect from light and moisture.

Reconstituted solutions should be aliquoted and stored at -20°C. The peptide is light-sensitive.

Testing Methods

Melanotan II batches should be verified by:

RP-HPLC for purity (≥98% recommended)

Mass spectrometry for identity confirmation

Research Limitations

Melanotan II is supplied for in vitro laboratory research and animal model studies only. Melanotan II has been associated with significant adverse effects in humans, including nausea, flushing, and blood pressure changes. It is not approved for human therapeutic use by any regulatory authority. No medical, therapeutic, or dosing claims are made.

References

1.Dorr RT, et al. Melanotan II and Pigmentation. J Invest Dermatol. 2004;123(1):184-185.
2.Hruby VJ, et al. Melanocortin Receptors. Med Res Rev. 2011;31(1):1-49.
3.Cone RD. The Central Melanocortin System. Endocr Rev. 2006;27(7):736-749.

Research use only. This article is for educational purposes only and does not constitute advice for any application involving human use. No medical claims are made.