Melanotan II

Classification

Cyclic melanocortin receptor agonist (research only)

Approval status

Research only · Not approved for human use

Research status

Not approved. TGA has warned consumers about Melanotan products.

Molecular formula

Insufficient reliable evidence identified.

Molecular weight

Insufficient reliable evidence identified.

Sequence

Cyclic lactam analogue of α-MSH: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2.

Primary biological target

Melanocortin receptors (non-selective relative to labelled bremelanotide)

Half-life

Insufficient reliable evidence identified.

Routes investigated

Subcutaneous (unapproved / illicit markets), Experimental

Human evidence level

C — Limited or early human evidence

An unapproved melanocortin peptide used illicitly for tanning. It is not a cosmetic sunscreen and not a registered tanning medicine.

Synthetic melanocortin agonist developed experimentally; diverted to unapproved tanning use.

Proposed mechanism

Proposed mechanism: MC1R-mediated melanogenesis and broader melanocortin effects (including autonomic and sexual signalling). Mechanism not yet fully established as a legal therapeutic. Unapproved tanning injections have documented harm reports.

Can darken skin via eumelanin pathways and cause systemic melanocortin effects. This is pharmacology, not a spa tan.

• Pigmentation (unapproved)

  C · Limited or early human evidence

  Has been investigated experimentally for pigmentation. This is not an approved indication; regulators warn against use.^[1]

Investigational findings are not proven clinical benefits unless an authority has labelled that indication.

Overall human evidence grade: C · Limited or early human evidence

Early clinical work existed; MT-II was not approved. Public-health agencies have warned against its use.

Animal, cell and in-vitro findings are listed separately from human effects.

Melanocortin pigmentation biology is real — and so are systemic receptor effects.

This section does not provide personalised medical dosing. Values are those reported in papers or protocols. Animal mg/kg doses are not converted to human doses.

Doses reported in human studies

Insufficient reliable evidence identified.

Preclinical / animal study dosing

Insufficient reliable evidence identified.

Reliable human pharmacokinetic data were not identified for this encyclopaedia entry, or are limited to product information for approved presentations.

Nausea, flushing, appetite change, spontaneous erections, mole darkening.

Serious events. Case reports of melanoma concern, rhabdomyolysis and serious systemic reactions in the unapproved-use literature — see regulator warnings.

Unknowns. Product contamination is common in illicit supply.

Contraindications. Not for human use. Particularly hazardous for people with melanoma risk. Not for children.

Australia — TGA

Not approved. Consumer warnings against Melanotan I/II.

United States — FDA

Not approved for tanning.

European Union — EMA

Not approved for tanning.

1. [1] TGA consumer warnings on Melanotan

   Therapeutic Goods Administration TGA consumer warnings on Melanotan 2023

   Open source