Comparison
Two melanocortin tanning peptides with different selectivity, side-effect profiles, and regulatory histories.
Melanotan-1 (the afamelanotide lineage) reached an approved implant for a rare photosensitivity disease; melanotan-2 is the unapproved community staple with broader effects and more side effects.
Both stimulate melanogenesis through MC1R. Melanotan-2 is less selective across melanocortin receptors, which explains its stronger tanning reputation and its extra effects: nausea, flushing, appetite suppression, and libido changes: the same pharmacology that eventually produced PT-141 (bremelanotide).
Afamelanotide, the drug form of the melanotan-1 lineage, is an approved 16 mg subcutaneous implant for erythropoietic protoporphyria. Melanotan-2 is unapproved everywhere and has drawn regulator warnings, including an FDA action against a vendor in 2016 and later TGA and Health Canada warnings about tanning products.
Both are used as loading-then-maintenance injections: commonly 250 to 500 mcg daily loading for MT-2 (around 500 mcg to 1 mg for MT-1), then weekly maintenance. Dermatology concerns center on darkening of existing moles and the unknown long-term effect of stimulating melanocytes with an unapproved drug.
| Dimension | Melanotan-1 | Melanotan-2 |
|---|---|---|
| Overall evidence grade | B | D |
| Evidence label | Strong human evidence | Limited human evidence |
| Regulatory status | Varies by product and jurisdiction | Not FDA-approved for listed uses |
| Editorial confidence | High confidence | Moderate confidence |
| Efficacy | 4/5 substantial | 1/5 limited |
| Safety | 3/5 emerging | 1/5 limited |
| Regulatory risk | 3/5 moderate | 5/5 very high |
| Product quality risk | 5/5 very high | 5/5 very high |
| Primary claim categories | Afamelanotide alias mapping, Approved EPP photoprotection context, MC1 receptor pathway, Tanning and cosmetic claims, Unregulated melanotan product risk, Melanocortin-family comparison | Unapproved tanning-product context, Melanocortin receptor pathway, Gray-market product-quality risk, Skin and pigmentary safety concerns, Libido and performance claim context |
Melanotan-1 usually points back to afamelanotide, but Scenesse evidence is narrow to EPP and separate from unregulated melanotan products.
Melanotan-2 is not an FDA-approved tanning product. Regulators tie it to unregulated tanning-market promotion, and approved melanocortin drug labels do not transfer to it.
FDA. Scenesse (afamelanotide) approval letter, NDA 210797 2019.
Accessed 2026-07-18.
FDA approval letter identifying afamelanotide (Scenesse) as an approved implant for erythropoietic protoporphyria; replaces the earlier EPP workshop slide deck (now offline) as the alias and evidence-boundary source.
FDA. Notice of Opportunity for Hearing (NOOH) Manookian, Edward 8/5/16 2016.
Accessed 2026-06-09.
FDA enforcement source describing Melanotan II as an unapproved new drug marketed as an injectable tanning product; used only for regulatory-risk and claim-boundary framing.
Other. Don't risk using tanning products containing melanotan 2025.
Accessed 2026-06-09.
Australian TGA warning source for melanotan I/II tanning products, online promotion, unapproved-product quality risk, adverse-event concerns, and advertising restrictions.