Unapproved research chemicalHuman evidence

Melanotan II

Also referred to as MT-2, MT-II

Retained in the catalogue primarily to document a substantial body of reported harm. The published case literature is the relevant evidence here.

Molecule class: Non-selective melanocortin receptor agonist
Category: Melanocortin
Last evidence review: 2026-08-24

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Human studies

Animal / in vitro

Graded claims

—

Participants

Mechanism

What is being studied

Non-selective melanocortin agonist. Non-selectivity across MC1R through MC5R underlies both the pigmentary effect and much of the adverse-effect profile.

Evidence

Claims, graded individually

Each statement below carries its own evidence level, its own confidence rating, and its own account of what remains unestablished. A compound does not have a single grade.

Dermatologic & Tissue Research

CPreliminaryModerate confidenceHuman evidence

Published case literature documents melanocytic naevus change, melanoma diagnosed in users, rhabdomyolysis, renal injury, and posterior reversible encephalopathy syndrome associated with melanotan II use.

What is not established

Case literature cannot establish incidence or causation, but multiple national regulators have issued specific warnings on the basis of it.

Supporting sources (1)

Case seriesHumanNo verified identifier on file

Melanotan II safety reports and case literature

Multiple · Dermatology and toxicology case literature · 2019

Population: Case reports and small series among unsupervised users
Endpoint: Adverse event reporting
Route: Subcutaneous
Quantity as reported: Unsupervised, self-reported quantities
Frequency: Varies

Result. Published case literature describes changes in melanocytic naevi, reports of melanoma diagnosed in users, rhabdomyolysis, renal injury, and posterior reversible encephalopathy.

Adverse events. This record exists specifically to document reported harms rather than an efficacy endpoint.

Limitations. Case literature cannot establish incidence or causation, but the volume and severity of reported signals are themselves the relevant finding.

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Last evidence review: 2026-08-23

Human evidence

1 human study catalogued

Human and non-human evidence are kept strictly separate. They are never pooled, averaged, or presented as a single body of support.

Case seriesHumanNo verified identifier on file

Melanotan II safety reports and case literature

Multiple · Dermatology and toxicology case literature · 2019

Population: Case reports and small series among unsupervised users
Endpoint: Adverse event reporting
Route: Subcutaneous
Quantity as reported: Unsupervised, self-reported quantities
Frequency: Varies

Result. Published case literature describes changes in melanocytic naevi, reports of melanoma diagnosed in users, rhabdomyolysis, renal injury, and posterior reversible encephalopathy.

Adverse events. This record exists specifically to document reported harms rather than an efficacy endpoint.

Limitations. Case literature cannot establish incidence or causation, but the volume and severity of reported signals are themselves the relevant finding.

Search PubMed for this literature →

Pharmacology

Reported parameters

Half-life

33 hours

Reported at approximately 33 hours, though characterisation is limited.

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Routes studied

Subcutaneous

Evidence from one route does not transfer to another. Topical, oral, and injected administration can produce entirely different exposure from the same quantity.

Regulatory status

Not approved anywhere for human use. Multiple national regulators have issued specific consumer warnings about this compound. FDA removed melanotan II from the Category 2 list effective 22 April 2026 after the nominators withdrew. This is a withdrawal of a nomination, not a safety finding, and a further advisory committee meeting covering it is scheduled before 28 February 2027.

Storage as documented

No approved labelling exists.

Safety

Signals reported in the literature

This lists what has been reported. It is not a complete safety profile, and for several compounds in this catalogue no systematic safety surveillance exists at all.

Case reports of changes in melanocytic naevi and of melanoma diagnosed in users
Reported rhabdomyolysis and renal injury
Reported posterior reversible encephalopathy syndrome
Nausea, flushing, and spontaneous erections are commonly reported

Interactions

Register entries involving this compound

melanotan-ii ↔ photosensitising medications

The dermatologic case literature for this compound already includes naevus change and melanoma reports. Concurrent photosensitising agents compound an already-documented concern.

Limitations. No formal interaction studies exist.

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Limitations

What the evidence cannot tell you

Given as much prominence as the findings, because for most compounds in this category it is the more important half.

Case literature cannot establish incidence, but the volume and severity of reported signals is itself the finding
No controlled efficacy or safety programme supports non-clinical use

Reference

Evidence grading key

AStrong

Multiple high-quality human trials, or strong systematic-review or meta-analytic evidence.

BModerate

Human controlled evidence exists, but replication or sample size is limited.

CPreliminary

Small human studies, observational evidence, or early-phase clinical work.

DPreclinical

Predominantly animal or in-vitro evidence. No adequate human outcome data.

EMechanistic

Biological plausibility or mechanistic reasoning without adequate outcome evidence.

XInsufficient / conflicting

Evidence is absent, irreconcilable, or too weak to support any directional statement.

Other compounds studied in the same research areas

Bremelanotide

A melanocortin agonist with two phase 3 randomised trials in premenopausal women with hypoactive sexual desire disorder. Effect sizes were modest.

GHK-Cu

The most credible human evidence is topical and cosmetic. Injected use is not adequately studied and should not be treated as equivalent.