Comparison
Afamelanotide vs. Plecanatid
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Research other
Research other
CAS no.
75921-69-6
467426-54-6
Molecular weight
1646.87 g/mol
1682 g/mol
Half-life
12 h
no data
Sequence
Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2no data
Mechanism of action
Afamelanotide
Afamelanotide is a synthetic analogue of α-melanocyte-stimulating hormone. It differs from native α-MSH by two substitutions — norleucine at position 4 and D-phenylalanine at position 7 — which make it metabolically more stable and more potent. As an agonist at the melanocortin-1 receptor (MC1R) on melanocytes, it activates adenylate cyclase, raises cAMP and increases tyrosinase activity via the transcription factor MITF. This shifts pigment synthesis toward eumelanin, which absorbs UV and visible light and has antioxidant properties — the presumed mechanism of photoprotection in EPP.
Plecanatid
Plecanatide is structurally analogous to the body's own uroguanylin and, like it, activates the GC-C receptor at the gut surface, raising cGMP and fluid secretion. Its pH-dependent activity shifts the effect toward the proximal small intestine.
Evidence base
Highest evidence
Human RCT
Human RCT
Studies
4
0
of which in humans
4
0
Effects recorded
4
2
Open conflicts
1
1
Documented adverse events
4
1
Legal status
Full entries
Frequently asked questions
- What is the difference between Afamelanotide and Plecanatid?
- Afamelanotide is classified as "Research other", while Plecanatid is classified as "Research other". Afamelanotide: Afamelanotide (brand name Scenesse) is a synthetic 13-amino-acid analogue of α-melanocyte-stimulating hormone (α-MSH) and a melanocortin-1 receptor agonist. Unlike most peptides covered here, it is a regularly approved medicine: EMA approval in 2014/2015, FDA approval in 2019, in each case as a subcutaneous implant for the prevention of phototoxicity in adults with erythropoietic protoporphyria (EPP). It promotes eumelanin formation in the skin. Plecanatid: Plecanatide is a 16-amino-acid analog of the body's own uroguanylin and a guanylate cyclase-C (GC-C) agonist. It is approved for chronic idiopathic constipation (CIC) and IBS with constipation (IBS-C). This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, Afamelanotide or Plecanatid?
- The highest available evidence level is "Human RCT" for Afamelanotide and "Human RCT" for Plecanatid. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.
- What is the legal status of Afamelanotide and Plecanatid in Germany and the United States?
- Germany: Afamelanotide — Prescription, Plecanatid — Unapproved. United States: Afamelanotide — Prescription, Plecanatid — Prescription. These are factual summaries with source and review date on the individual pages.