Cagrilintide research peptide: identity, structure and COA reference

PubChem gives the cagrilintide sequence as KCNTATCATQRLAEFLRHSSNNFGPILPPTNVGSNTP, with a C20 fatty diacid (icosanedioic acid) attached through a gamma-glutamate linker to the N-terminal amine of Lys1, a disulfide bridge between Cys2 and Cys7, and an amidated C-terminal proline. Lined up against human amylin (UniProt P10997, KCNTATCATQRLANFLVHSSNNFGAILSSTNVGSNTY), the backbone differs at six positions: N14E, V17R, A25P, S28P, S29P and Y37P.

The proline substitutions at 25, 28 and 29 are the same ones used in pramlintide to reduce amylin's tendency to aggregate. The fatty-diacid side chain promotes albumin binding, the same design idea used in semaglutide's C18 diacid, which is why cagrilintide is so often compared with GLP-1 class peptides even though it is not a GLP-1 receptor agonist.

In the 2021 Journal of Medicinal Chemistry paper that introduced it, cagrilintide is characterized as a non-selective agonist of the amylin receptors (AMY1R, AMY2R, AMY3R) and the calcitonin receptor. That makes it a reference compound for laboratories studying amylin and calcitonin receptor pharmacology, receptor selectivity, and peptide fibrillation and stability.

Cagrilintide is also one component of CagriSema, a fixed combination with semaglutide that Novo Nordisk is studying in clinical trials. As of October 2026 Novo Nordisk states CagriSema is not approved in the US, and cagrilintide is not approved on its own anywhere. Research-grade cagrilintide is not that product, is not made or labeled for human or animal use, and nothing here describes or supports such use.

Because cagrilintide is a large, acylated, disulfide-bridged peptide, HPLC purity alone says little about whether the vial holds the right molecule. These checks matter most:

1. Identity by mass: LC-MS (or MALDI) with an observed mass that matches 4409.0 Da average, or the ion series m/z 1470.7 (3+), 1103.3 (4+), 882.8 (5+). A missing fatty-diacid and linker side chain would read about 454 Da light; an open (reduced) disulfide reads 2 Da heavy.
2. Purity with a chromatogram: reversed-phase HPLC area percent with the trace, not a bare 'above 98%'. Acylated peptides elute late and can tail, so the integration window matters.
3. Lot match: the lot number on the vial equals the lot on the report, and the report states the labeled quantity (for example 10 mg).
4. Measured quantity: an assay result for how much peptide is in the vial, because HPLC purity is not net peptide content.
5. Correct identifiers: CAS 1415456-99-3 and formula C194H312N54O59S2. A different CAS, or a molecular weight near 3,903 g/mol (unmodified human amylin), suggests the document describes a different molecule.

Vitality Chems lists cagrilintide in a 10 mg vial for laboratory research. Before relying on any lot, open its report by lot number on the verify page and run it through the COA checklist. If a lot report does not include LC-MS identity, request it from the testing page before ordering rather than assuming it.