Melanotan II
Skin Health
In short
- A non-selective melanocortin receptor agonist that stimulates melanogenesis, producing tanning without UV exposure.
- Not approved anywhere. Regulatory agencies in several countries have issued explicit consumer warnings against it.
- Non-selectivity is the problem: it hits MC1R (pigmentation), MC4R (libido, appetite), and others simultaneously.
- Case reports document new and changing melanocytic naevi, and at least one melanoma diagnosis following use.
- The dermatological concern is not theoretical — it is the reason regulators name this compound specifically.
Structure
How it works
Melanotan II is a cyclic analogue of alpha-melanocyte stimulating hormone. Agonism at MC1R on melanocytes drives eumelanin synthesis, darkening the skin without UV exposure.
Because it is non-selective it also activates MC3R and MC4R, producing the well-known secondary effects on libido, appetite suppression, and spontaneous erections. PT-141 was developed as a more selective descendant of this molecule.
What the research shows
It produces pigmentation reliably and rapidly, which is the effect users seek and is not in dispute.
What has never been established is safety. There is no completed trial characterising long-term consequences, and the compound is supplied by unregulated vendors with no verification of identity or purity.
Dosing in the literature
Figures below are quoted from published studies, with the species or population they were measured in. They are records of what was studied, not recommendations.
| Studied in | Amount | Route | Source |
|---|---|---|---|
| Human — early melanocortin research studies | Microgram-per-kilogram ranges in small investigational studies | subcutaneous | PubMed |
Commonly reported ranges
These are amounts people report using. They are not from any study, have not been evaluated for safety, and are reproduced here only because they circulate widely and are better seen alongside the evidence than instead of it.
| Reported by | Amount | Route |
|---|---|---|
| Commonly reported loading phase | 250–500 µg daily | subcutaneous |
| Commonly reported maintenance | 500 µg–1 mg once or twice weekly | subcutaneous |
No published human pharmacokinetic study establishes a dose, interval, or duration for this compound. Community figures below have no trial behind them and are reports of practice, not evidence. This is also the compound in this library that regulators have most specifically warned consumers against, and the case-report literature concerns pigmented lesions rather than dosing.
Handling and storage
Lyophilised powder requiring reconstitution and refrigeration. Subcutaneous injection.
Nausea is commonly reported as worst on early doses and is often the reason smaller initial amounts are described.
Side effects
Very common: nausea (often significant on early doses), facial flushing, spontaneous erections in men, appetite suppression, and darkening of existing moles and freckles.
The serious concern is dermatological. Case reports document eruptive and changing melanocytic naevi following use, and there is at least one published report of melanoma diagnosed in a user. Because the compound darkens existing lesions, it can also mask the visual changes that ordinarily prompt investigation of a suspicious mole — a mechanism for delayed diagnosis independent of whether it causes anything.
Rhabdomyolysis and posterior reversible encephalopathy have appeared in isolated case reports.
Combinations
Combining with PT-141 duplicates melanocortin agonism and compounds nausea and pigmentation.
No interaction data exists. The consistent advice in the dermatology literature is not about stacking but about skin surveillance.
Research status
Originally developed at the University of Arizona as a potential photoprotective agent. Never completed clinical development. The published human literature is dominated by case reports of adverse dermatological events rather than efficacy studies.
Regulatory agencies including the UK MHRA and Australia's TGA have issued specific warnings.
Legal status
Not approved in any jurisdiction. Sale for human consumption is illegal in the UK, Australia, and elsewhere, and multiple agencies have issued consumer alerts naming it. Sold online labelled for research use only.
WADA status
Not specifically named on the WADA Prohibited List as of this review date. Falls under S0 as an unapproved substance and should be treated as prohibited in sport.
Conclusion
Melanotan II works — it is one of the few compounds here where the intended effect is undisputed and visible. That is exactly why the safety question deserves more weight, not less.
If you use it, the non-negotiable is dermatological surveillance: photograph your moles, know what they looked like before, and get changes examined. The compound darkens the very lesions you would otherwise be watching.
Sources
Track your own Melanotan II protocol
Peppers logs your doses, models your levels from this half-life, tracks your vials and tells you when you will run out. Free on iPhone.
Reference and educational information only. Not medical advice. Nothing here diagnoses, treats, or prescribes, and nothing here is a recommendation to use any compound. The compounds described are research chemicals and are not approved for human consumption. Legal and anti-doping status change — the review date above is when these claims were last checked. Talk to a qualified clinician about anything you intend to take.