Melanotan 1 and Melanotan 2 share a name, an origin — both came out of the University of Arizona's melanocortin work in the late 1980s and 1990s — and a target, the receptors that alpha-MSH switches on. Their records went in opposite directions. Melanotan 1 became afamelanotide, an approved implant with a fixed dose and a narrow indication. Melanotan II never reached approval; its close relative bremelanotide did, for something else. This page sets the two records side by side from the labels and literature (read 2026-10-11), lines up every dose figure in milligrams, and does the syringe arithmetic. It compares; it recommends neither.
The single-compound records are on the Melanotan 1 and Melanotan II dosage pages, which carry the full trial details; vial arithmetic for any water volume is on the Melanotan 1 calculator and the Melanotan II vial-and-water settings.
Side by side
| Melanotan 1 (afamelanotide) | Melanotan II | |
|---|---|---|
| Structure | Linear, 13 residues, [Nle4, D-Phe7]-α-MSH | Cyclic, 7 residues |
| Molecular weight | 1,646.85 | 1,024.2 |
| Main receptor action | Melanocortin-1 (pigment) | Several melanocortin receptors (pigment, sexual response, appetite) |
| Approved product | SCENESSE, 16 mg implant | None |
| Labelled dose | One implant every 2 months | — |
| Human study doses | 0.08–0.21 mg/kg SC (1997) | 0.01–0.03 mg/kg SC; 0.025 mg/kg in all three studies |
| Approved relative | — (it is approved) | Bremelanotide (VYLEESI), 1.75 mg as needed |
| Case reports on PubMed (2026-10-11) | Mostly attributed to unlicensed "melanotan" products | Same reports; most name Melanotan II |
| WADA 2026 | Not named; approved, so outside S0 | Not named; S0 wording reaches it |
Every dose figure in milligrams
| Figure | Source | Amount | At 70 kg |
|---|---|---|---|
| SCENESSE implant | Label | 16 mg every 2 months | ≈0.27 mg a day averaged |
| Afamelanotide, 1997 SC study | Ugwu, PMID 9113347 | 0.08–0.21 mg/kg | 5.6–14.7 mg a dose |
| Melanotan II trials | Dorr 1996; Wessells 1998, 2000 | 0.025 mg/kg | 1.75 mg a dose |
| VYLEESI (bremelanotide) | Label | 1.75 mg as needed, ≤8 a month | 1.75 mg |
| Melanotan 1, online | Protocol page (on the Melanotan 1 page) | 250 mcg | 0.25 mg |
| Melanotan II, online | Vendor pages (on the Melanotan II page) | 100–1,000 mcg | 0.1–1 mg |
Three things stand out from the table, all arithmetic on the cited figures. The 1990s injection doses of Melanotan 1 were far larger than anything circulating now — one 0.16 mg/kg dose at 70 kg is more than a 10 mg vial. The online Melanotan 1 figure, 250 mcg, sits close to the implant's daily average, which is a different exposure: the implant releases slowly over weeks. And the Melanotan II trial dose for a 70 kg adult equals bremelanotide's labelled dose, 1.75 mg, which reflects how close the two molecules are.
Pigment, and everything else
Afamelanotide was developed and approved for one effect, darker skin that protects people with erythropoietic protoporphyria from light-triggered pain; its label measures pain-free hours in sunlight, not tanning. Melanotan II's wider receptor activity is the reason its studies were in erectile dysfunction and the reason its relative became a sexual-desire drug: nausea and spontaneous erections were among the effects reported in its studies. A reader comparing the two for "tanning" is comparing one molecule approved for photoprotection in a rare disease with one never approved for anything.
The case-report record
The 28 PubMed case reports tagged "melanotan" (2009–2026), grouped by this site from their titles:
| Theme | Reports |
|---|---|
| New or changing moles, eruptive naevi, lentigines | 11 |
| Melanoma (including in situ and oral mucosal) | 3 |
| Oral mucosal pigment change | 1 |
| Priapism | 2 |
| Renal infarction; rhabdomyolysis with systemic toxicity; PRES; pyoderma gangrenosum; nail pigmentation | 1 each |
| Other (use patterns, product identification, public-health notes) | 6 |
Case reports show that something happened to someone; they do not establish how often or that the product caused it, and most involve injections bought online whose contents were not analysed. What they do establish is that the reports cluster around unlicensed Melanotan II and "melanotan" products rather than the approved implant.
Units, same vial, different figures
Units depend only on concentration, so the two compounds read identically for the same amount. The difference is in the amounts.
| Amount | 10 mg in 1 mL (10 mg/mL) | 10 mg in 2 mL (5 mg/mL) | 10 mg in 3 mL (3.33 mg/mL) | 5 mg in 2 mL (2.5 mg/mL) |
|---|---|---|---|---|
| 250 mcg (Melanotan 1 online figure) | 2.5 | 5 | 7.5 | 10 |
| 500 mcg | 5 | 10 | 15 | 20 |
| 1,000 mcg | 10 | 20 | 30 | 40 |
| 1,750 mcg (Melanotan II trial scale, 70 kg) | 17.5 | 35 | 52.5 | 70 |
A 10 mg vial holds forty 250 mcg amounts, or five and a bit 1.75 mg amounts, at any water volume.
What is not established
No study has compared the two or given either to people for cosmetic tanning. Afamelanotide's evidence is for one rare disease and one implant; no label covers an injected solution. Melanotan II's three studies total 23 men. The case-report literature cannot be turned into a rate. Product and dose decisions belong with a clinician. The compounds are covered in Medibact's Melanotan 1 guide and Melanotan II guide.
Sources and dates
Opened 2026-10-11: the SCENESSE label record on openFDA (set id 94f53286-11dd-7fbb-e053-2a95a90a7c48, effective 2026-05-11) and the VYLEESI label record (set id f1d0c1b5-2f39-4bad-a6a4-0066e3ad5dcf, effective 2025-11-13), indications, dosage and strengths; PubMed searches for Melanotan II (243 records) and for melanotan case reports (28 records, titles read); ClinicalTrials.gov counts (afamelanotide 23, melanotan 1); the 2026 WADA Prohibited List in Tractatenblad 2026 no. 25, S0. Carried from this site's pages with their read dates: the Melanotan II trial record, molecular weights and vendor range (Melanotan II page, 2026-09-19) and the afamelanotide injection study and 250 mcg protocol figure (Melanotan 1 page, 2026-09-27). Milligram, implant and unit arithmetic by this site. Corrections go to the contact page.