Cosmetic
Melanotan I (Afamelanotide)
DO NOT CONFLATE THIS WITH MELANOTAN II — that is the single most common error made about this compound, and the two behave differently enough that the mistake matters.
Also known as MT-1 · MT-I · Melanotan 1 · Afamelanotide · NDP-alpha-MSH · [Nle4-D-Phe7]-alpha-MSH · Scenesse
At a glance
Dose summary
No reliable human half-life has been published for Melanotan I (Afamelanotide), so none is listed rather than guessed at.
Reconstitution
What to draw, at the usual vial
A 10 mg vial reconstituted with 2 mL of bacteriostatic water gives 5.00 mg/mL. A typical 500 mcg dose is 0.100 mL — pull the plunger to 10 units on a U-100 syringe.
Same dose, other vial sizes
| Vial | Water | Concentration | Draw | Units | Doses |
|---|---|---|---|---|---|
| 10 mg | 2 mL | 5.00 mg/mL | 0.100 mL | 10 units | 20 |
The highlighted row is the one quoted above: the smallest listed vial that holds at least four typical doses. Change any of it — a different vial, more or less water, a different dose — on the reconstitution calculator, which draws the syringe to true U-100 graduations.
Mechanism & evidence
What it is, and what is known
DO NOT CONFLATE THIS WITH MELANOTAN II — that is the single most common error made about this compound, and the two behave differently enough that the mistake matters. Melanotan I is the LINEAR alpha-MSH analogue [Nle4-D-Phe7]-alpha-MSH (afamelanotide): a 13-amino-acid straight-chain peptide that is essentially alpha-MSH with two residues swapped for stability, and it is relatively SELECTIVE FOR MC1R, the melanocyte receptor.
Melanotan II is a smaller CYCLIC seven-residue peptide that hits MC1R, MC3R, MC4R and MC5R non-selectively. The MC3R/MC4R activity is where Melanotan II gets its spontaneous erections and priapism reports, its heavy nausea and vomiting, its yawning/stretching reaction and its appetite suppression. MELANOTAN I DOES NOT SHARE THAT PROFILE: it is not an erectogenic drug (that pharmacology is what PT-141/bremelanotide was developed from, and bremelanotide is a Melanotan II derivative, not a Melanotan I derivative), and its nausea and appetite effects are much weaker.
What it does share is melanogenesis, and therefore the mole and melanoma-surveillance concern. THE APPROVAL STATUS IS ALSO DIFFERENT, AND THIS IS THE OTHER HALF OF THE CONFUSION. Afamelanotide IS an approved medicine: as SCENESSE it holds EMA approval (2014) and FDA approval (2019) for erythropoietic protoporphyria (EPP), a rare inherited photosensitivity disorder, where it increases eumelanin and raises the time patients can tolerate light exposure.
Melanotan II is approved nowhere. That approval does NOT transfer to cosmetic use. The approved product is a 16 mg controlled-release SUBCUTANEOUS IMPLANT inserted by a trained clinician above the hip every two months, in a monitored EPP program that includes regular skin surveillance. It is not a self-injected lyophilized vial and it is not a nasal spray. The vials and sprays sold as "Melanotan 1" are unlicensed research-chemical product of unverified purity, with no approved label to anchor dosing to.
The 250-1000 mcg daily figures here are grey-market convention only: Melanotan I is generally used at higher milligram totals than Melanotan II because it is less potent per microgram at MC1R uptake in practice, typically a daily loading phase until the target pigmentation is reached, then a much less frequent maintenance dose. Published pharmacokinetic figures for the free peptide are inconsistent and the implant PK is dominated by the release rate rather than the peptide, so no half-life is listed.
Anyone using it should have a dermatologist skin check before starting and be monitored during and after, and it does not replace sun protection.
Tolerability
Reported side effects
- Darkening of existing moles and freckles, and appearance of new naevi. Melanocortin-driven pigmentation makes an existing lesion harder to read dermoscopically, which is the reason for the active-malignancy flag here as well as on Melanotan II
- Facial flushing and warmth shortly after dosing
- Nausea, but markedly less common and less severe than with Melanotan II
- Injection site pain, redness or itching
- Headache and mild fatigue
- Uneven or blotchy pigmentation rather than an even tan, especially at low or irregular dosing
- Reported in the afamelanotide implant trials: nausea, headache, back pain, fatigue and implant-site reactions
Hard stops
Do not use this if
- Pregnancy, possible pregnancy, or breastfeeding
- Active, suspected or recently treated malignancy
- Under 18
These are flags, not a screening. They do not replace a conversation with a clinician who knows your history.
Handling
Storage
Keep it cold, keep it dark, and label the vial with the date you mixed it. Discard anything cloudy or past the window above.
Combinations
Commonly stacked with
Stacking multiplies the side-effect surface and makes it impossible to tell which compound did what. Add one thing at a time.
References
Sources
Educational information only, not medical advice. Talk to a licensed clinician before starting, changing, or stopping anything.