Afamelanotide vs Melanotan I

Evidence-based comparison. Updated 2026.

Afamelanotide and Melanotan I are the same compound: Melanotan I is the research name, while Afamelanotide is the international nonproprietary name used in clinical and regulatory contexts. Both refer to the FDA-approved synthetic alpha-MSH analog marketed as Scenesse for erythropoietic protoporphyria. There is no meaningful clinical distinction to choose between them.

Side by side

	Afamelanotide	Melanotan I
Evidence	AEvidenceGrade ALarge human randomised controlled trials, or FDA / major-authority approved	AEvidenceGrade ALarge human randomised controlled trials, or FDA / major-authority approved
Regulatory	FDA approvedFDA approvedApproved by the US Food and Drug Administration for at least one use	FDA approvedFDA approvedApproved by the US Food and Drug Administration for at least one use
Benefits	Stimulates melanin production and skin pigmentation Provides photoprotection against UV radiation Reduces photosensitivity in erythropoietic protoporphyria Improves skin tolerance to sun exposure May reduce phototoxic reactions in porphyria patients	Induces skin pigmentation and tanning Provides photoprotection against UV damage Reduces photosensitivity in erythropoietic protoporphyria Melanocortin receptor agonist activity Fewer systemic side effects than Melanotan II
Dosage	16 mg, 1x every 2 days	0.5-1 mg, 1x daily
Route	Subcutaneous	Subcutaneous
Category	Tanning & Pigmentation	Tanning & Pigmentation

Full research page

Afamelanotide

Full research page

Melanotan I

Which should you choose

Afamelanotide and Melanotan I are functionally identical peptides sharing the same amino acid sequence and mechanism of action at MC1R. The naming difference reflects terminology used in different research and regulatory contexts rather than any structural or pharmacological distinction.

Choose Afamelanotide when

Use the term Afamelanotide when referencing FDA-approved clinical use, prescriptions, or peer-reviewed literature published after regulatory approval.
Afamelanotide is the designation used by healthcare providers and regulatory bodies when discussing the implantable formulation for erythropoietic protoporphyria management.
Clinical trial data, safety profiles, and approved dosing protocols are indexed under Afamelanotide, making it the preferred term for evidence-based research review.

Choose Melanotan I when

Melanotan I is the terminology more commonly encountered in early preclinical and pharmacology literature from the 1980s and 1990s, making it useful when reviewing foundational research.
Researchers studying melanocortin receptor pharmacology in experimental settings often use the Melanotan I designation to distinguish it from Melanotan II, which has a different receptor selectivity profile.
Melanotan I is the term more frequently used when discussing the compound in the context of photoprotection research outside of the EPP indication specifically.

Stacking Afamelanotide with Melanotan I is not applicable because they are the same molecule, and combining them would simply constitute a dose increase rather than a mechanistically distinct combination.

Questions people ask

Is there any clinical or pharmacological difference between Afamelanotide and Melanotan I?

No. Afamelanotide and Melanotan I refer to the same synthetic peptide with the sequence Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2. The difference is purely nomenclature: Melanotan I was the original research designation, while Afamelanotide became the internationally accepted nonproprietary name used in regulatory submissions and clinical practice.

How does choosing between the Afamelanotide label and the Melanotan I label affect research or sourcing decisions?

For clinical or regulatory purposes, Afamelanotide is the correct and legally recognized designation, particularly in jurisdictions where the compound is approved under that name. Melanotan I may appear in older literature or research databases, and recognizing both names helps researchers avoid duplicating literature searches or confusing it with Melanotan II, which is a structurally different peptide with broader receptor activity and a distinct side effect profile.

How does Afamelanotide or Melanotan I differ from Melanotan II in terms of receptor selectivity and side effects?

Unlike Afamelanotide or Melanotan I, which are selective MC1R agonists, Melanotan II is a non-selective melanocortin receptor agonist that also activates MC3R, MC4R, and MC5R. This broader receptor engagement is associated with side effects including spontaneous erections, nausea, and appetite suppression that are not characteristic of Afamelanotide. This is a critical distinction when reviewing research, as Melanotan II data should not be extrapolated to Afamelanotide or Melanotan I.

If both names describe the same peptide, why do some sources list them separately as if they are different compounds?

The conflation arises because early melanocortin research produced multiple analogs simultaneously, and the Melanotan I and Melanotan II designations were assigned in parallel, leading some databases and secondary sources to catalog them separately without clarifying that Afamelanotide is simply the adopted nonproprietary name for Melanotan I. Researchers should verify amino acid sequences when comparing studies to confirm which compound was actually used rather than relying on naming conventions alone.

Not sure which fits your research goals?

Use the goal finder

Answer three questions and get a peptide recommendation ranked by evidence grade.

Find my peptide