Skip to content
Peptide Evidence Registry

Melanocortin

Melanotan II

A synthetic melanocortin peptide sold for tanning — unapproved everywhere, and routinely confused with genuinely approved melanocortin medicines.

L2Animal / lab studiesResearch / unapproved supplyUnclear
How settled this rating is:
very-low confidence in the current evidence rating
Routes studied:
Not established · Subcutaneous injection, Nasal (marketed but never approved)
Also known as:
MT-II, MT2, melanotan
Last reviewed:
2026-08-23
Jump to section

Evidence passport

Melanotan II

A one-screen evidence identity for this compound. These fields describe research maturity, confidence and legal status. They are not a safety guarantee, efficacy percentage or recommendation.

Reviewed 2026-08-23
Evidence level
L2Animal / lab studies
Confidence
Very low confidence in rating
Regulatory status
Research / unapproved supply
Development status
Unclear

Evidence strength

Human efficacy evidence15 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Human safety evidence10 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

The 0-100 values rate the strength and maturity of evidence, not how effective or safe the compound is.

Evidence base
Mostly animal and laboratory research
Furthest established stage
Not established
Human research maturity
Limited early human study; no approved development programme
Source curation
Sources fully curated

Routes recorded

SC injection· unapprovedNasal· unapproved

Most of this evidence comes from animals and cells

The supporting research for Melanotan II is predominantly preclinical (Level 1–2). That is a legitimate starting point for science and a poor basis for personal decisions. Human results are not simply a scaled-up version of mouse results.

Overview

Human efficacy evidence strength15 of 100 evidence strength

Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.

Preclinical (animal / lab) evidence strength55 of 100 evidence strength

Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.

Human safety evidence strength10 of 100 evidence strength

Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number.

How to read these scores

Every number here rates the evidence, not the compound. They are editorial 0-100 strength ratings, not percentages, and not a rating out of five stars.

  • Human efficacy evidence strength — Higher = more and better-quality human evidence. It does not mean the effect is bigger or that the compound works for you.
  • Preclinical evidence strength — Higher = more animal, tissue or cell research. Preclinical results are a starting point, not proof of a human benefit.
  • Human safety evidence strength — Higher = more mature, better-documented human safety data. It does not mean the compound is safer than one with a lower number. A score of 80 does not mean “80% safe”.
  • Evidence level (L0-L5) — the strongest type of study behind the compound, from anecdote (L0) to large replicated human trials (L5). It is a description of the study evidence, not a quality, safety or recommendation rating.
  • Confidence — how likely we think it is that this rating changes as new research lands. Low confidence means the picture is unsettled, not that the compound is bad.

None of these ratings is medical advice, a safety guarantee, or a recommendation to use anything. How we grade evidence.

How far human research has progressed: Limited early human study; no approved development programme

Routes & formulations

Marketed / research routes — never approved

SC injection· unapprovedNasal· unapproved

Marketed in the research market as injections and nasal sprays. No approved formulation exists for any route, and tanning-market availability is not evidence of efficacy or safety.

Route availability is not evidence of efficacy, and evidence from one route does not transfer to another. The Registry never provides dosing or sourcing information.

Peptide lifecycle

  1. Discovery

  2. Preclinical

  3. Phase I

  4. Phase II

  5. Phase III

  6. Approved

UnclearFurthest stage not established in our curated record

No active approved development programme in the curated record; early research history only.

What it is

A synthetic cyclic analogue of alpha-MSH developed in early skin-cancer-prevention research, later leaking into the unregulated tanning market.

What people claim

  • Tans the skin without sun exposure
  • Suppresses appetite
  • Increases libido

What the evidence actually says

Skin darkening is a real pharmacological effect of MC1R activation — that was never in doubt. What does not exist is a demonstration that Melanotan II is a safe or approvable medicine, and regulators have consistently said the opposite. A visible effect is not evidence of safety, and it is not the same thing as approval of the distinct melanocortin medicines that did complete development.

Related evidence

Useful next reads based on this compound — not recommendations.

Human evidence

  • Small early-phase human studies of pigmentation and sexual effects; no adequate controlled safety or efficacy programme.

Preclinical evidence

  • Melanocortin receptor pharmacology and animal pigmentation studies.

Animal and cell findings are Level 1–2 evidence.

Mechanism and pathways

  • Non-selective melanocortin receptor agonism: MC1R drives skin pigmentation; MC4R activity relates to appetite and sexual effects.

Safety and unknowns

  • Spontaneous sexual effects and nausea are documented pharmacological effects, reported in early studies and adverse-event literature.
  • There is no systematic long-term human safety dataset; FDA's compounding classification reflects identified significant safety risks.
  • Unapproved supply quality is a separate and serious risk.

Cancer relevance

This section covers questions raised by how the compound works in the body, plus anything regulators and trial teams keep an eye on. It is not a statement that this compound causes cancer — for most compounds here, no human data exist in either direction.

Theoretical / mechanistic concern only

A recurring concern is that stimulating melanocytes could interact with melanoma risk. No human data demonstrate that Melanotan II causes cancer — and none establish it is safe in that respect. Unstudied is not reassuring.

Regulatory status

Regulatory decisions apply to specific jurisdictions, products, formulations and indications. An approval elsewhere is not automatically an approval in your country.

Check the regulatory note and linked primary sources for jurisdiction-specific details.

Not an approved medicine in any major region and identified by FDA as a bulk substance presenting significant safety risks for compounding. It must not be confused with the approved melanocortin medicines bremelanotide, afamelanotide and setmelanotide, each of which has its own narrow, specific indication.

Evidence grade

L2Animal / lab studiesVery low confidence in rating

Documented compound-specific animal or laboratory outcome findings, without qualifying human evidence for the assessed benefit.

What would change our rating?

  • A completed, regulator-quality clinical programme — which, notably, no sponsor has pursued to approval.

References and sources

Source transparency

A provenance snapshot of this profile. Counts show what kinds of sources are cited, not how much scientific weight each source deserves.

Sources fully curated
Last editorial review
2026-08-23
Recently reviewed · 54 days ago
Linked curated sources
3
Sources still pending
0
External specialist reviews
0
None recorded for this profile
Regulatory / label: 3

Review provenance

Registry editorial review: Colin Jackson-White, creator and editor, who is not a doctor or clinician. External specialist review is credited only when a named reviewer has completed a review of this exact profile.

Literature-discovery and AI tools may help locate or challenge candidate evidence, but they are not counted as evidence sources here. Registry judgements are tied to the underlying papers, trial records, regulator documents and official study records.

Source hierarchy: regulatory documents and trial registries first, peer-reviewed work next, sponsor material flagged as non-independent. We never use supplier or clinic marketing as evidence, and where a verified source has not yet been curated we say so rather than inventing one.

Evidence change history

These entries record changes to our assessment of the published evidence — not changes to the compound itself.

No recorded changes yet. Baseline position set on 2026-08-23.

Related claims we’ve checked — in full

Claim verdict

Melanocortin

MisleadingL2Animal / lab studies

“Melanotan II is basically the same approved medicine as afamelanotide.”

This verdict applies to the exact claim above. It is not a verdict on the compound overall, a safety guarantee, or a recommendation to use it.

Registry verdict

Misleading — related chemistry, completely different regulatory reality.

Why this verdict

  • Afamelanotide (Scenesse) completed a full development programme and is approved for one rare disease, erythropoietic protoporphyria, as a clinician-administered implant.
  • Melanotan II has no approval anywhere and sits on the FDA's 503A Category 2 list of substances with identified significant safety risks for compounding.
  • Saying 'it's basically the approved one' erases the entire difference between a finished trial programme and an abandoned one.