Melanotan I is an unusual compound to write a dosage page about, because it has a great deal of evidence and almost none of it is filed under the name a buyer would search.
It also has a real, current FDA label — and that label describes a dose that cannot be converted into the form the compound is sold in.
One molecule, two names, and only one of them is in the registry
Afamelanotide is melanotan I. It is a synthetic tridecapeptide analogue of α-melanocyte stimulating hormone and a melanocortin receptor agonist binding predominantly to MC1-R, in the SCENESSE label's own words.
ClinicalTrials.gov, intervention search, 21 September 2026:
| Search term | Interventional studies |
|---|---|
afamelanotide |
23 |
melanotan |
1 |
The 23 include three phase 3 studies in erythropoietic protoporphyria at 74, 93 and 100 participants, a phase 2 confirmatory study at 77, a 100-participant multicentre phase 3, an implant pharmacokinetic and pharmacodynamic study at 24, and a 200-participant active comparison against narrow-band UVB that is still active.
The one is NCT07437560. Its brief summary opens:
This example interventional study record describes…
It is also a melanotan II record, not melanotan I. So under the name this compound is actually sold by, the registry holds nothing at all — and the one thing it appears to hold disclaims itself in its own first sentence, with no status, phase or enrolment field to reveal it. This site recorded the same trap on a different compound on 20 September; it is a reading rule now, not an anecdote.
The evidence base and the product name do not meet. Anyone checking "melanotan 1" against the registry finds a void and concludes the compound is unstudied. The opposite is true, and the search term is the whole difference.
The labelled dose
SCENESSE, from Clinuvel. FDA label effective 11 May 2026. Indicated to increase pain-free light exposure in adult patients with a history of phototoxic reactions from erythropoietic protoporphyria.
| Form | Subcutaneous implant |
|---|---|
| Strength | 16 mg afamelanotide |
| Interval | Every 2 months |
| Site | Above the anterior supra-iliac crest |
| Administered by | A healthcare professional trained in the implantation procedure, using a dedicated cannula |
The dosing section is a procedure: aseptic technique, local anaesthetic, sterile gloves, blunt forceps to remove the implant from its glass vial, a specified cannula, and instructions for removing the implant afterwards.
There is no labelled injection dose for this molecule, in any amount, at any interval. That is not an omission. The approved product is a solid controlled-release implant, and the label's dose figure is inseparable from that form.
Why the interval cannot be carried across
The label's pharmacokinetics were measured in 12 healthy adults given a single implant:
| Parameter | Value |
|---|---|
| Median Tmax | 36 hours |
| Mean Cmax | 3.7 ± 1.3 ng/mL |
| Mean AUC0-inf | 138.9 ± 42.6 h·ng/mL |
| Apparent half-life | ≈ 15 hours |
| Last measurable concentration | 96 hours post-dose in 9 of 12 subjects |
Three things in that table decide the question.
A 36-hour time to peak is not a peptide property. A tridecapeptide injected as a solution does not take a day and a half to reach maximum plasma concentration. That figure is the implant dissolving.
The label attaches its own condition to the half-life — approximately 15 hours when administered subcutaneously in a controlled release implant. An apparent half-life measured under release-limited conditions describes the release, not the clearance. This site's half-life chart carries the figure in exactly those terms, because printing it beside true clearance half-lives in the same column is the error the chart exists to prevent.
The concentration is gone long before the next dose. Last measurable concentration at 96 hours, against a two-month interval. The dosing interval is not built around plasma levels at all — it is built around how long the pigmentary effect lasts after the peptide has cleared.
So a per-injection equivalent of "16 mg every two months" does not exist, and cannot be derived by arithmetic. Dividing 16 mg across 60 days produces a number with no experiment behind it.
What the approved evidence covers, and what it does not
The label's pharmacodynamics section states that afamelanotide increases production of eumelanin in the skin independently of exposure to sunlight or artificial UV light sources. That is a mechanism statement in an approval document, and it is why the drug works for erythropoietic protoporphyria.
It is not a finding about cosmetic use. The trials enrolled people with a rare inherited porphyria, and the endpoint was pain-free light exposure in a population for whom light causes phototoxic reactions. The label also directs that sun and light protection measures be maintained during treatment — which is the inverse of the setting the compound is marketed into.
Both things are true at once, and this site's rule is to state them together: the molecule has a genuine approval dossier, and the dossier answers a question that is not the one the market is asking.
Method
The SCENESSE label was read through the openFDA drug label API on 21 September 2026; the effective time, indication, dosing section and clinical pharmacology quoted above come from that record. The ClinicalTrials.gov v2 API was queried the same day for afamelanotide and melanotan as intervention terms, and the brief summary of NCT07437560 was opened and read rather than inferred from its structured fields. Related records on this site: the dosage chart grades every compound by the tier of source behind its figure, how to read a dosing claim sets out why a form-bound dose does not convert, and the melanotan 2 dosage record is a separate molecule with a separate and much thinner evidence file. Nothing on this page is a dosing instruction.