# Melanotan II

> Evidence tier A — Controlled human trials · Hormones & Drive · reviewed 2026-11-08
> Source page: https://peptidemeta.com/p/melanotan-ii/

Also known as: MT-II, Melanotan 2

## Quick answers

**What is Melanotan II?**

A synthetic melanocortin peptide that stimulates melanogenesis, producing a tan without UV exposure. Not the same as afamelanotide (Scenesse), a different, linear α-MSH analogue that the FDA and EMA have approved for erythropoietic protoporphyria.

**How strong is the evidence for Melanotan II?**

Tier A (controlled human trials) on the peptidemeta evidence scale. Small double-blind, placebo-controlled crossover trials in men with erectile dysfunction (1998, 2000) and phase 1 tanning studies. Never approved anywhere.

**Is Melanotan II FDA-approved?**

No. Melanotan II is not approved by the FDA for any use.

**Is Melanotan II banned in sport?**

Yes. Melanotan II is prohibited in sport by the World Anti-Doping Agency under S0 (non-approved substances).

**How does Melanotan II work?**

Melanotan II is a cyclic heptapeptide analog of alpha-MSH that non-selectively activates melanocortin receptors MC1R through MC5R. MC1R activation on melanocytes stimulates cAMP signaling and tyrosinase expression, increasing eumelanin synthesis and skin pigmentation.

**What is known about the safety of Melanotan II?**

Small human trials reported nausea, stretching/yawning, fatigue/somnolence, and spontaneous erections. Concerns from case reports include darkening of moles that may complicate melanoma detection and priapism in males.

## Key facts

- **Evidence tier:** A (Controlled human trials)
- **FDA:** not approved
- **WADA:** prohibited (S0)
- **Peptide:** yes
- **Sequence:** [Ac][Nle]DH[D-Phe]RWK[NH2] (7 residues)
- **Formula:** C50H69N15O9
- **Molecular weight:** 1024.2 g/mol
- **Routes studied:** Subcutaneous, Intramuscular

## Overview

A synthetic melanocortin peptide that stimulates melanogenesis, producing a tan without UV exposure. It also has notable sexual arousal and appetite-suppressive side effects.

## Mechanism

Melanotan II is a cyclic heptapeptide analog of alpha-MSH that non-selectively activates melanocortin receptors MC1R through MC5R. MC1R activation on melanocytes stimulates cAMP signaling and tyrosinase expression, increasing eumelanin synthesis and skin pigmentation. MC4R activation produces the sexual arousal and appetite-suppressant side effects.

## Effects reported in research

_Reported outcomes, not promises; see the evidence tier._

- Increased melanin production and skin tanning
- Enhanced libido as a side effect
- Mild appetite suppression
- Darkened moles and nevi (monitor closely)

## Safety & unknowns

Small human trials reported nausea, stretching/yawning, fatigue/somnolence, and spontaneous erections. Concerns from case reports include darkening of moles that may complicate melanoma detection and priapism in males. Not FDA-approved. Multiple regulatory agencies have issued warnings about unlicensed products.

## Studies

- Dorr RT, Lines R, Levine N, et al. (1996). *Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study*. Life Sciences. Clinical trial. https://pubmed.ncbi.nlm.nih.gov/8637402/
  Single-blind, placebo-controlled pilot phase I study in 3 healthy men; MT-II increased skin pigmentation in 2 subjects and caused mild nausea, somnolence, and spontaneous erections.
- Wessells H, Gralnek D, Dorr R, et al. (2000). *Effect of an alpha-melanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction*. Urology. Clinical trial. https://pubmed.ncbi.nlm.nih.gov/11018622/
  Double-blind, placebo-controlled crossover trial in 10 men in which Melanotan II initiated erections more often than placebo, with nausea and yawning as common side effects.

## Status sources

- [Wessells et al. 2000 — randomized placebo-controlled crossover trial (Urology)](https://pubmed.ncbi.nlm.nih.gov/11018622/)
- [Wessells et al. 1998 — double-blind placebo-controlled crossover study (J Urol)](https://pubmed.ncbi.nlm.nih.gov/9679884/)
- [Dorr et al. 1996 — pilot phase 1 study of melanotan-II (Life Sci)](https://pubmed.ncbi.nlm.nih.gov/8637402/)
- [PubChem CID 92432 (melanotan II)](https://pubchem.ncbi.nlm.nih.gov/compound/92432)
- [WADA 2026 Prohibited List — S0 non-approved substances](https://www.wada-ama.org/sites/default/files/2025-09/2026list_en_final_clean_september_2025.pdf)

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Educational reference only — not medical advice. No dosing information is published. Tiers rate the strength of published evidence, not effectiveness or safety.