Melanotan I (Afamelanotide)

Overview

Melanotan I, as a medicine called afamelanotide, is the substance that emerged from the original research programme with an approval. It is licensed in the EU under the name Scenesse for erythropoietic protoporphyria — a rare genetic condition in which sunlight causes severe pain.

For that indication it is administered as an implant under medical supervision, releasing over roughly two months. That is a different situation from an injection self-administered for cosmetic tanning, and the approval should not be read as covering the latter.

Its practical relevance in the scene is limited, and the reason is instructive: MT-I lacks exactly the side effects that make MT-II unpleasant — and one effect that many consider a feature.

Mechanism of Action

Melanotan I is largely selective for the MC1R receptor, the one in the pigment cells of the skin. Melanotan II binds MC1R, MC3R and MC4R alike.

That difference in selectivity explains everything that distinguishes the two. MT-I produces pigmentation without meaningfully engaging the receptors responsible for nausea, appetite suppression and sexual effects. The tolerability is considerably better — the intense nausea and facial flushing typical of the first MT-II injections are largely absent.

The flip side is that the erectile effect, which many people using MT-II regard as a welcome addition, does not occur. This is the main reason MT-I plays a smaller role in the scene despite being the cleaner substance.

Per microgram, MT-I is less potent for pigmentation, which is why the doses used are higher.

What both share is the effect on moles, because that comes from the MC1R activity they have in common. Existing naevi darken and can enlarge, and this remains the central risk of both substances.

Typical Context

Off-label, MT-I is used for tanning in the same pattern as MT-II: a loading phase followed by maintenance dosing, at somewhat higher doses because of the lower potency.

The sensible reason to choose it over MT-II is tolerability. Anyone who found MT-II unbearable because of the nausea, or who does not want the sexual side effects, gets the pigmentation effect here without them.

The reason it is nonetheless less common is straightforward: it is harder to obtain, more expensive, and for a large part of the user base the missing MC4R effect is a loss rather than a gain.

Its approval status deserves a clear word, because it is sometimes used as an argument for safety. Scenesse is approved for a specific rare disease, in a specific implant form, under medical supervision, with a documented benefit-risk assessment for patients who cannot tolerate sunlight at all. None of that transfers to grey-market vials injected for a tan.

Side Effects & Risks

• Darkening, enlargement and new appearance of moles — the same risk as MT-II
• Uneven pigmentation; freckles and scars darken disproportionately
• Local reactions at the injection site
• Nausea — considerably milder than with MT-II but not absent
• Fatigue, headache occasionally
• Grey-market product has no approval and unverified quality

Blood Work & Monitoring

As with MT-II, the relevant monitoring is dermatological rather than laboratory-based:

• Dermatological mole documentation — before starting and at regular intervals
• Complete blood count — as a baseline

Harm-Reduction Notes

• The mole risk is identical to MT-II — dermatological documentation before starting is the key measure
• Not for anyone with many naevi or a family history of melanoma
• The approval covers a rare disease in implant form; it says nothing about cosmetic injection
• Better tolerated than MT-II — the sensible choice if nausea or sexual side effects were the problem
• Higher doses needed than with MT-II due to lower potency
• Pigmentation persists for months after stopping
• Does not replace sun protection
• Only sources with an independent analysis for grey-market product