What is Melanotan II (Melanotan 2)?

Introduction:

Melanotan II (Melanotan 2, MT-II) is a synthetic peptide analog of α-melanocyte-stimulating hormone (α-MSH), a naturally occurring hormone that regulates skin pigmentation.¹ Initially developed in the 1980s as a potential treatment for skin disorders such as erythropoietic protoporphyria and vitiligo, Melanotan II has since been studied for its ability to increase skin pigmentation through activation of melanocortin receptors.²

While widely discussed as a “tanning peptide,” Melanotan II remains a research chemical, not approved for medical or cosmetic use by the FDA or EMA. ³

Discovery & Development

Originated at the University of Arizona in the 1980s, where researchers were exploring sunless tanning agents.¹
Built as a short, stable analog of α-MSH, improving its half-life and activity compared to the natural hormone.²
Early studies tested Melanotan II in skin pigmentation disorders and sexual dysfunction, but it never achieved regulatory approval.³

How It Works

Insert Figure 1: Diagram of Melanotan II binding to MC1R receptors in melanocytes.
ALT: “Diagram showing Melanotan II binding to melanocortin receptors to stimulate pigmentation.”
Caption: “Figure 1. Melanotan II stimulates pigmentation via melanocortin receptor activation.”

Melanotan II activates melanocortin receptors (MC1R, MC3R, MC4R, MC5R).¹
Its primary effect is MC1R activation in melanocytes, stimulating increased production of melanin, the pigment responsible for skin color.
Secondary effects include appetite modulation and sexual arousal pathways, due to MC3R/MC4R activity. ²

Research Applications

Pigmentation disorders: Investigated for use in vitiligo and erythropoietic protoporphyria.²
Skin protection: Studied for potential reduction of UV-related skin damage.³
Sexual function: Explored as a treatment for erectile dysfunction and female sexual arousal disorder. ³

Limitations

Not FDA-approved for any indication.
Safety data is limited; concerns exist about nausea, mole darkening, and unregulated supply.³
Most current use occurs in unregulated markets as a research chemical.

Summary

Melanotan II (Melanotan 2) is a synthetic analog of α-MSH designed to stimulate skin pigmentation by activating melanocortin receptors. Initially developed for tanning and skin disorders, it has also been researched for sexual function and metabolic effects. However, it remains research-only, with no regulatory approval for medical or cosmetic use.

FAQs About Melanotan II

Is Melanotan II FDA-approved?

No, it is not approved by the FDA or EMA and is considered a research chemical.

What does Melanotan II do?

It increases melanin production in the skin by activating melanocortin receptors, leading to darker pigmentation.

What was Melanotan II originally developed for?

It was developed as a tanning agent and studied for pigmentation disorders and sexual dysfunction.

References

Hadley ME, et al. “Discovery and development of melanocortin peptides for tanning and skin protection.” Ann N Y Acad Sci. 1999;885:342–356. https://pubmed.ncbi.nlm.nih.gov/10816663/
Wessells H, et al. “Effect of melanocortin receptor agonist Melanotan-II in men with erectile dysfunction: a randomized controlled trial.” Arch Neurol. 2000;57(4):449–455. https://pubmed.ncbi.nlm.nih.gov/10768691/
US FDA. “Melanotan II not approved for tanning or cosmetic use.” FDA Safety Bulletin. https://www.fda.gov/consumers/consumer-updates/tanning-pills-and-injections