Melanotan I
$FDA-approved MC1R agonist for EPP; Not a cosmetic tanning protocol
Melanotan I is the older research name for afamelanotide, the active drug in SCENESSE. Unlike Melanotan II, it has an FDA-approved prescription form: a 16 mg controlled-release implant for adults with erythropoietic protoporphyria (EPP).
The strongest evidence is for EPP, where afamelanotide increases pain-free light exposure. It has also been studied with narrowband UVB in vitiligo, but that is not the same as approval for cosmetic tanning or online powder self-injection.
Separate three things: the approved SCENESSE implant, dermatology research uses such as vitiligo plus NB-UVB, and gray-market injectable “Melanotan I” products. The safety and PK data from the approved implant should not be automatically applied to unregulated powders.
Melanotan I is a synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH). Its pharmaceutical name is afamelanotide. The molecule is a 13-amino-acid melanocortin analog with substitutions that make it more stable than native alpha-MSH, including norleucine at position 4 and D-phenylalanine at position 7. The approved drug form is SCENESSE, a bioresorbable 16 mg subcutaneous implant.
Classification details
- This is important: the approved product is not a vial of powder for home injection. It is inserted by a trained healthcare professional and has a controlled-release pharmacokinetic profile.
- Classification: melanocortin receptor agonist, primarily discussed as an MC1R-focused pigmentation and photoprotection agent. It is related to Melanotan II, but it is not the same molecule. Melanotan II is cyclic, nonselective, and unapproved. Afamelanotide is linear, more MC1R-focused, and approved for a narrow medical indication.
- The FDA-approved afamelanotide/SCENESSE implant context is separate from unapproved Melanotan I research/cosmetic products. The approved product is a controlled-release implant for erythropoietic protoporphyria, not a generic tanning powder protocol.
- Afamelanotide binds predominantly to melanocortin-1 receptor (MC1R) on melanocytes. MC1R activation increases cyclic AMP signaling and stimulates eumelanin production.
- Eumelanin is the darker pigment associated with increased photoprotection compared with pheomelanin.
- For EPP, this does not cure the porphyrin pathway defect. Instead, it increases the skin pigment barrier and raises the amount of light exposure a patient can tolerate before phototoxic pain occurs.
- Patients are still advised to maintain sun and light protection measures.
- Compared with Melanotan II, afamelanotide is less defined by MC3R/MC4R central effects. This is why the libido, spontaneous erection, appetite, and severe nausea profile associated with MT-II does not carry over to Melanotan I as if the two were identical.
- MT1 primarily activates MC1R to increase eumelanin and photoprotection. This differs from Melanotan II, which has broader melanocortin activity and more libido/erectile effects.