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Peptide Library
Skin & Hair Research

Melanotan II

Also referenced as: MT-2, MT-II

An unregulated tanning peptide with documented case-report harms and no approval.

Evidence grade
EExperimental / Limited Evidence

Experimental / Limited Evidence

Regulatory status
Not FDA Approved

Not approved anywhere as a medicine. Multiple regulators have issued warnings against unlicensed tanning injections. Afamelanotide, a different and more selective analogue, is separately approved for a rare photosensitivity disorder — the two should not be conflated.

Human data
Limited

No registered clinical trials identified

Last reviewed
September 1, 2026

Overview

Melanotan II is a non-selective melanocortin agonist that stimulates melanin production. It is sold online for cosmetic tanning despite regulatory warnings in multiple countries.

This entry exists for scientific literacy rather than as a research recommendation: the case-report literature is unusually clear about harm.

Why It's Being Studied

  • Melanogenesis and photoprotection mechanisms.
  • Melanocortin receptor pharmacology, which led to more selective approved analogues.

Mechanism of Action

In plain language

It switches on the pigment-producing cells in skin, causing tanning without sun exposure, while also acting on other body systems.

Technical detail

Melanotan II is a cyclic lactam alpha-MSH analogue with non-selective agonism at MC1R (pigmentation), MC3R and MC4R (appetite, sexual function) and MC5R. Non-selectivity explains its broad off-target effects.

Interactive diagram

Skin remodelling and the hair cycle

Tap each stage to see what happens.

Signal: Copper peptides or other signals reach dermal cells.

Background: Skin & Hair Research

Skin and hair research looks at collagen synthesis, wound closure, pigmentation and the hair-follicle cycle.

Topical cosmetic research is often industry-funded and small. Injected use of cosmetic peptides has little human data.

Research Areas & Routes Studied

Areas studied
  • Pigmentation
  • Melanocortin pharmacology
Routes used in research
  • Subcutaneous injection (unregulated use)

Evidence Summary

Human data are limited to small early studies and a substantial case-report literature documenting harm, including melanoma and systemic effects after unregulated use.

Evidence pyramid

Higher tiers carry more weight. Filled tiers have evidence for Melanotan II; tap to read it.

Human clinical trials
  • Small early pharmacology studies only; no efficacy or safety programme was completed.
Source breakdown

2 cited sources.

  • Observational study1
  • Regulatory document1

Human clinical evidence

  • Small early pharmacology studies only; no efficacy or safety programme was completed.

Observational evidence

  • A substantial case-report literature documents changing and new melanocytic lesions, melanoma diagnoses, rhabdomyolysis, renal injury and priapism following unregulated use.

Anecdotal / community information

  • Cosmetic tanning forums; reports frequently omit adverse outcomes.

Reported Adverse Events in Research

  • Nausea, flushing, spontaneous erections, appetite suppression.
  • Darkening and change of existing naevi; melanoma has been reported after use.
  • Case reports of rhabdomyolysis and renal injury.
  • Unregulated products of unknown identity and sterility add infection risk.

Limitations of Current Evidence

  • No controlled safety data at any dose.
  • Regulatory warnings exist specifically because of documented harm.

How to Read This Research

Questions to ask
  • Was the product topical or injected?
  • Were results measured by instruments or by photos and self-assessment?
  • Who funded the study?
Reading tips
  • Cosmetic claims face a lower evidence bar than medical claims.
  • Pigmentation-affecting compounds carry documented risks, including changes in moles.
Anagen
The active growth phase of a hair follicle.
Dermis
The skin layer beneath the surface that holds collagen.
Melanocortin
A hormone family that affects pigmentation and appetite.

Compare With Other Compounds

Compare side by side
Melanotan IIGHK-Cu
Evidence gradeE — Experimental / Limited EvidenceC — Early Human Research
Regulatory statusNot FDA ApprovedNot FDA Approved
Human dataLimitedLimited
Clinical trialsNone identifiedNone identified
Research routesSubcutaneous injection (unregulated use)Topical, Intradermal (cosmetic research)
Cited sources22

Frequently Asked Questions

Why It Is Used

  • Sexual Health

    Libido and Sexual Function

    One of the few categories where the leading compound is FDA approved — and where its close relative is a clear example of what unselective signalling costs.

    Read the case study

Research References

  • Observational study

    Melanoma and melanocytic lesions after melanotan use: case reports

    View Study
  • Regulatory document

    Regulatory warnings on unlicensed tanning injections

    View Source
This page is an educational research summary. It is not medical advice, does not recommend human use, and does not provide individualised dosing. Many compounds discussed here are research use only and are not approved medicines.