Peptide reference · Lipidated amylin analog
Cagrilintide COA check: molecular weight, formula and what to look for
Use these reference values to check the identity result on a Cagrilintide Certificate of Analysis. The theoretical average molecular weight of Cagrilintide is 4,409.01 Da and the monoisotopic mass is 4,406.252 Da.
Check a Cagrilintide COA nowCagrilintide reference data
| Name | Cagrilintide |
|---|---|
| Also known as | NN9838, AM833 |
| Type | Lipidated amylin analog |
| Molecular formula | C194H312N54O59S2 |
| Average molecular weight | 4,409.01 g/mol (Da) |
| Monoisotopic mass | 4,406.2515 Da |
| Reference source | PubChem CID 171397054 (formula and mass cross-checked) |
Expected mass spectrometry ions
A Cagrilintide COA may list one of these m/z values instead of the neutral mass. That is still consistent with Cagrilintide. How charge states work.
| Ion | m/z (monoisotopic) | m/z (average) |
|---|---|---|
| [M+3H]3+ | 1,469.76 | 1,470.68 |
| [M+4H]4+ | 1,102.57 | 1,103.26 |
| [M+5H]5+ | 882.26 | 882.81 |
| [M+6H]6+ | 735.38 | 735.84 |
What else can show up on a Cagrilintide COA
Masses calculated from Cagrilintide's formula for the adducts, degradation products and synthesis impurities a lab report can show. A match tells you what the extra peak probably is.
| Signal | Value | What it means |
|---|---|---|
| Na adduct, deconvoluted (M + 21.98) | 4,428.23 Da | Sodium adduct: an MS artifact, not a separate impurity. The [M+Na]+ ion itself is at M + 22.99 |
| K adduct, deconvoluted (M + 37.96) | 4,444.21 Da | Potassium adduct: an MS artifact. The [M+K]+ ion itself is at M + 38.96 |
| TFA adduct (M + 113.99) | 4,520.24 Da | Trifluoroacetic acid from purification seen as an adduct; residual TFA salt is real vial content |
Adduct rows are deconvoluted masses (the shift seen against [M+H]+); the singly charged [M+Na]+ ion itself sits at M + 22.99. Deletion masses alone can't say which copy of a repeated residue is missing.
At over 4 kDa, Cagrilintide is harder to purify; 98% or higher with one sharp main peak is a strong result. The full checklist is in how to read a peptide COA.
Cagrilintide-specific things to watch
Cagrilintide is a long-acting, lipidated amylin analog with a disulfide bond, about 4409 Da average.
At this size the average and monoisotopic masses differ by about 3 Da. A good COA states which one it reports and shows the deconvoluted spectrum.
Amylin analogs are prone to aggregation, so HPLC traces with broad or shouldered main peaks deserve a closer look even if the purity number seems high.
Cagrilintide's charge ladder sits near 1,470.7 (3+), 1,103.3 (4+) and 882.8 (5+) m/z, calculated from the average mass. If the disulfide bond isn't formed, the mass is about 2 Da higher.
Cagrilintide is often sold blended with semaglutide, a pairing modeled on Novo Nordisk's CagriSema combination. A blend COA should report identity and amount for each peptide separately, near 4,409.1 Da and 4,113.6 Da.
Compounds with similar mass
If a COA's mass is off, compare it with these neighbors. A match to one of them can point to a mislabeled product.
- Semaglutide: 4,113.58 Da (-295.43 Da)
- Retatrutide: 4,731.35 Da (+322.34 Da)
- Tirzepatide: 4,813.45 Da (+404.44 Da)
Sources
- PubChem CID 171397054: Cagrilintide formula and reference mass.
- CIAAW: Standard atomic weights: Used to calculate average molecular weights.
- NIST CODATA: proton mass: Used to convert m/z charge states to neutral mass.
- PeptideCOACheck methodology: How the checker's thresholds work.
Last updated . Written and maintained under our editorial policy. Found an error? See corrections.
Frequently asked questions
What does 1103.3 m/z mean on a cagrilintide COA?
The 4+ ion of the 4,409.1 Da molecule.
What should a cagrilintide and semaglutide blend COA show?
Separate identity and quantity results for each peptide. A single purity figure for the blend can't confirm both.
Why do cagrilintide HPLC traces sometimes show broad peaks?
Amylin analogs tend to aggregate. A broad or shouldered main peak deserves a closer look even if the purity number is high.
For laboratory research use only. This page describes analytical chemistry data. It is not medical advice and makes no claim about effects in humans or animals.