How to Read a Cagrilintide Certificate of Analysis (COA)
A Certificate of Analysis is only useful if you know which number on it matters for the compound in front of you. For Cagrilintide, the informative checks are not the same as for a generic short peptide.
Overview
Look for a weight near 4409 on the report. There is a second thing worth checking that people miss: this molecule has an internal sulfur-to-sulfur bridge between positions 2 and 7, and a version with that bridge wrongly connected weighs exactly the same as a correct one. A purity percentage cannot tell those apart, so any identity data speaking to the bridge is more useful than a higher purity number.
What Cagrilintide actually is
Cagrilintide is an engineered copy of amylin — a hormone released from the pancreas at the same time as insulin. The natural version has a well-known problem: it clumps into fibres very readily, which is why nobody could make a long-lasting version of it for years. Cagrilintide is that problem solved, with six changes to the sequence and a fatty chain attached to make it last about a week instead of half an hour.
Supplied for laboratory research use only — not for human or animal use.
Third-party tested by HPLC and LC-MS, ≥99% purity, with a Certificate of Analysis on every order. Ships across Canada.
Technical detail below
Assays that are informative for Cagrilintide
What to check on the COA
Confirm the mass near 4409 Da. Because the sequence carries a Cys2–Cys7 disulfide, correct disulfide pairing is a meaningful identity question that a purity percentage alone does not answer. As with other acylated peptides, aggregate content by size-exclusion chromatography adds information RP-HPLC cannot, since the organic mobile phase tends to dissociate soluble aggregates before they are detected.
Deletion sequences from a long synthesis, incompletely acylated chains, disulfide-scrambled isomers, and soluble aggregates.
Verify a Popular Peptides batch
Every batch is third-party tested by HPLC and LC-MS with a published Certificate of Analysis (≥99% purity). Enter a lot number to pull the COA for the exact vial in front of you.
What Cagrilintide is studied for
Cagrilintide binds the calcitonin receptor and all three amylin receptors (AMY1, AMY2, AMY3), which is why the literature sometimes classes it as a dual amylin and calcitonin receptor agonist.
A worked example of engineering a fibril-prone hormone into a stable long-acting analogue — salt-bridge helix stabilisation plus beta-sheet-breaking prolines.
The C20 diacid extends the half-life from minutes, for the short-acting analogue pramlintide, to roughly a week.
The most-studied context: co-administration with semaglutide, investigated in the REDEFINE trial programme.
Summarizes published preclinical literature — see the selected references below. Provided for research reference only; not a claim of efficacy or a description of human use.
- Lau DCW, Erichsen L, Francisco AM, et al. Once-weekly cagrilintide for weight management in people with overweight and obesity: a multicentre, randomised, double-blind, placebo-controlled and active-controlled, dose-finding phase 2 trial. Lancet. 2021.
- Garvey WT, Blüher M, Osorto Contreras CK, et al. Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2025.
- Davies MJ, Bajaj HS, Broholm C, et al. Cagrilintide–Semaglutide in Adults with Overweight or Obesity and Type 2 Diabetes. N Engl J Med. 2025.
- Browse current Cagrilintide literature on PubMed
References describe in-vitro and preclinical research and are listed for reference only — not evidence of efficacy and not a description of human use.
More Cagrilintide reference
Lyophilized and reconstituted storage conditions, plus the practical working window.
Diluent selection, dissolution behaviour, and the calculator preset for this compound.
Which solvents work, why, and what abnormal dissolution behaviour indicates.
The specific chemical routes by which this molecule breaks down, and how to limit each.
Compound-specific bench practices, and the errors most often made with this molecule.
What to inspect on arrival, and which conditions actually warrant rejecting a vial.
Questions specific to this compound — structure, chemistry, and common misconceptions.
Purity & COA reference for other compounds
Reviewed for research-use compliance by Kobi Williams, Founder — Popular Peptides Canada. Last reviewed 22 July 2026.
Cagrilintide is supplied strictly as a research chemical for in-vitro laboratory and research use only. It is not intended for human or animal consumption, diagnostic, or therapeutic use. This page is educational laboratory-handling reference information — not medical advice, not usage guidance, and not a protocol.