Melanotan II Not available

Skin

Melanotan II

An unapproved synthetic melanocortin peptide

Not FDA-approved · not available for sale or prescription
Why it’s not available
Stylised model of the real sequence

Overview.

Melanotan II has never been approved by any regulatory agency, and human evidence is limited to small early studies and case reports. It is a synthetic cyclic analog of alpha-melanocyte-stimulating hormone that stimulates pigment cells, darkening the skin, and in a small trial caused erections and increased reported sexual desire in men with erectile dysfunction. It is prohibited in sport under WADA's non-approved-substances class (S0) and has a documented history of an FDA warning letter, a federal criminal conviction and debarment, and case reports of serious harm including melanoma (a causal link has not been established).

Also known as MT-II · MT2 · Melanotan 2

The molecule, decoded.

Sequence

Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2

Length
7 residues
Molecular weight
1,024.2 g/mol
Formula
C50H69N15O9
CAS number
121062-08-6
Half-life
Not established (estimates range from about 1 hour to 33 hours)
Routes studied
subcutaneous injection
Modifications
Cyclic lactam (side-chain amide bond, Asp-Lys, forming a 23-membered macrocycle); N-terminal acetylated norleucine (Nle); D-Phe substitution at position 7; C-terminal amide

How it works.

Melanotan II is a non-selective agonist at melanocortin receptors MC1R, MC3R, MC4R, and MC5R. MC1R activation on melanocytes stimulates eumelanin production (skin darkening) independent of UV exposure, while MC4R activation in the CNS drives increased sexual desire/erectile response and appetite suppression.

Evidence · Early or small human studies

What the research shows

small crossover RCT2000

In a double-blind placebo-controlled crossover study, Melanotan II induced penile erection (without sexual stimulation) in 17 of 20 men with erectile dysfunction and increased reported sexual desire after 68% of active doses vs 19% of placebo doses.

20 men with psychogenic/organic erectile dysfunction

Source
small crossover RCT2000

Nausea and yawning were the most frequent adverse effects; severe nausea affected 12.9% of subjects at one dose level.

same cohort as above

Source
case reports2026

Published case reports describe melanoma, eruptive/dysplastic nevi and darkening of existing nevi, oral mucosal pigmentation and one oral mucosal melanoma, priapism, rhabdomyolysis and renal infarction with unsupervised Melanotan II use; a causal link to melanoma has not been established.

case reports, multiple

Source
regulatory2007

FDA issued a warning letter to Melanocorp Inc. for illegally marketing injectable Melanotan II, including false claims that it prevented skin cancer.

n/a - regulatory enforcement

criminal case2015

The president of a Melanotan II distribution company pleaded guilty to federal conspiracy charges related to illegal sale of the unapproved drug; judgment was entered in US District Court in 2015.

n/a - DOJ criminal case

Source

What to know first.

Based on: anecdotal reports only; human safety is not established.

Reported side effects

  • nausea
  • yawning
  • facial flushing

Cautions

  • case reports of melanoma and dysplastic nevus eruption - dermatologic monitoring concern given interference with mole surveillance
  • ischemic priapism
  • rhabdomyolysis and renal infarction reported
  • unregulated gray-market supply carries additional contamination/dosing-accuracy risk
  • no FDA-approved label or established safe human dose exists

Checked 2026-09

Where it stands.

Not FDA-approved · not available for sale or prescription. Melanotan II is not FDA-approved and is not available for sale or prescription. We profile it because people ask about it.
FDA
Not approved; never submitted for approval in the US or elsewhere
Compounding
Not eligible for 503A/503B compounding: not a component of any FDA-approved drug, no USP monograph and not on either bulks list. FDA previously placed Melanotan II in Category 2 of its interim bulks policy, citing immunogenicity/impurity risk and published case reports of melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism; the nomination was later withdrawn (FDA 'nominated but withdrawn' list, current as of Apr 22, 2026). All US supply is unregulated research-chemical/gray-market material.
Sport (WADA)
Prohibited at all times (in and out of competition) under S0 Non-Approved Substances: Melanotan II is not named on the WADA 2026 Prohibited List (no melanocortin category exists in S2), but as a substance with no regulatory approval for human use it falls under S0. The 2027 List adds 'peptides' to the S0 examples.
Enforcement
  • FDA warning letter to Melanocorp, Inc. for marketing unapproved injectable Melanotan II (2007)
  • Melanocorp president/owner Edward Manookian pleaded guilty (Mar 11, 2015) to two counts of conspiracy (18 U.S.C. 371); judgment entered Aug 28, 2015 (M.D. Tenn.)
  • FDA permanently debarred Edward Manookian (debarment order published Nov 14, 2016)
  • FDA placed Melanotan II in Category 2 (significant safety risks) of its interim bulks policy; nomination later withdrawn
References (3)
  1. nature.com · 3900582
  2. PubMed Central · PMC12942211
  3. U.S. FDA · notice opportunity hearing nooh manookian edward 8516

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