What masses should a CagriSema COA show?

Two. Cagrilintide is C194H312N54O59S2 with an average mass of 4409 g/mol in PubChem, and semaglutide is C187H291N45O59 with an average mass of 4113.58 g/mol in the FDA label. Monoisotopic values are 4406.25 and 4111.12 Da. A certificate that prints only one mass, or none, has not confirmed that both peptides are present.

Can a blend pass an identity test and still be wrong?

Yes. If the laboratory only checks that semaglutide is present, a vial missing cagrilintide passes. If it checks both, the ratio can still be far from the label, because identity says nothing about amounts. And a third peptide can be present alongside both. Read the report for two masses, two amounts, per-peptide purity and a statement on any other significant peaks.

Is CagriSema an approved medicine?

Published phase 3a trials describe cagrilintide and semaglutide given together as an investigational combination. The US FDA states that cagrilintide is not a component of any FDA-approved drug. Semaglutide on its own is the active ingredient of approved products such as Ozempic. A vial sold as the blend is therefore not an approved product, and only testing shows what it contains.

One of the 30 compound testing profiles

Cagrilintide and semaglutide blend

A cagrilintide and semaglutide blend is two different peptides in one vial, cagrilintide (C194H312N54O59S2, average mass 4409 g/mol) and semaglutide (C187H291N45O59, average mass 4113.58 g/mol); a test should identify both, measure each one separately, and compare each amount with its own label figure.

CagriSema is the name used in published phase 3a trials for the investigational combination of cagrilintide, a lipidated amylin analogue, with the GLP-1 receptor agonist semaglutide (Garvey et al., New England Journal of Medicine, 2025).

Test your Cagrilintide and semaglutide blend

Identity card

Formula: Not a single molecule (see note)
Average mass: Not published
Monoisotopic mass: Not published
Length: Not applicable
Modifications: None listed
Also sold as: CagriSema, Cagri-Sema, Cagrilintide/semaglutide
Note: A blend has no single formula or mass. It contains two components, each with its own PubChem record: cagrilintide, PubChem CID 171397054 (C194H312N54O59S2, average mass 4409 g/mol, monoisotopic 4406.25 Da, 37 residues with an N-terminal C20 fatty diacid and a Cys2 to Cys7 disulfide), and semaglutide, PubChem CID 56843331 (C187H291N45O59, average mass 4113.58 g/mol from the FDA label, monoisotopic 4111.12 Da, with a C18 fatty diacid on a hydrophilic spacer at lysine 26 per the FDA label). PubChem has no compound record for the name CagriSema. Identity testing should report a mass for each component.

Source: PubChem CID 171397054, Cagrilintide, PubChem CID 56843331, Semaglutide, Ozempic (semaglutide) prescribing information, section 11 Description.

Compare the mass printed on a certificate with the values above. The mass checker explains charge states and which mass a lab usually reports.

What usually goes wrong with Cagrilintide and semaglutide blend. Documented failure modes, with sources.

One component missing altogether

The simplest failure is a vial that holds only one of the two. Semaglutide is the active ingredient of approved medicines (Ozempic prescribing information), while the US FDA states that cagrilintide is not a component of any FDA-approved drug and cannot be used in compounding under federal law (FDA, unapproved GLP-1 drugs). A blend vial holding semaglutide alone still gives a clean semaglutide peak and a confident purity number. The report should list a measured mass for each peptide, or state that one was not found.

The ratio is not what the label says

A label that prints one total milligram figure hides how the two peptides are split, and the split is the point of a blend. Measuring it takes two characterised reference standards and two calibrations. Cagrilintide has no approved product, so ask how its standard was characterised. Testing of single-peptide semaglutide vials sold online has already found content 28.56% to 38.69% above the label (Ashraf et al., Journal of Medical Internet Research, 2024); in a blend each peptide can be off in a different direction, so the ratio can be wrong while the total looks close.

A purity figure that mixes two peptides

HPLC purity is normally the main peak's share of total peak area. A blend has two intended main peaks, so a single percentage could mean one peptide's share, both combined, or something else. Each peptide also brings its own related impurities: compounded semaglutide products have shown dimers, trimers and oxidised forms not seen in the originator (Kopp et al., Pharmaceutical Research, 2026), and cagrilintide's disulfide and asparagines add their own variants. A useful report names both main peaks and states how purity was calculated.

A third peptide nobody asked for

In the same 2026 study, one compounded semaglutide sample contained a component with a mass corresponding to tirzepatide, and another a component matching insulin glulisine (Kopp et al., 2026). Finding both expected peptides does not rule out a third. Only a full LC-MS run, in which every significant peak is assigned a mass rather than two expected values being looked up, shows whether anything else is present.

Which tests matter most

LC-MSSeparates the two peptides and assigns each a mass, so a missing component or an unexpected third peptide is seen rather than assumed away.
HPLC-UVNeeds a method that resolves both main peaks; purity should be reported per peptide, with the calculation stated.
HRMSGives accurate masses for both components and their small variants, such as deamidation in cagrilintide.
Counter-ion contentTwo peptides can arrive as different salts; knowing the counter-ion load lets each amount be stated as peptide.

Reading Cagrilintide and semaglutide blend results

A blend certificate should carry two mass lines, two amounts and two purity figures. A single mass, or one line reading identity confirmed, has not shown that the vial is a blend. The mass checker computes an expected mass from each sequence, and the amount testing lesson explains how measured content is compared with a label, applied here to each component separately. No common label amounts are listed because Tested.ph has not yet recorded blend listings.

Public Tested.ph results

No public Cagrilintide and semaglutide blend records yet

Each public Cagrilintide and semaglutide blend record will appear here with its identity, HPLC purity and measured amount against the label, once the first vial is tested.

FIG 13Amount against the label

Questions about testing Cagrilintide and semaglutide blend

What masses should a CagriSema COA show?: Two. Cagrilintide is C194H312N54O59S2 with an average mass of 4409 g/mol in PubChem, and semaglutide is C187H291N45O59 with an average mass of 4113.58 g/mol in the FDA label. Monoisotopic values are 4406.25 and 4111.12 Da. A certificate that prints only one mass, or none, has not confirmed that both peptides are present.
Can a blend pass an identity test and still be wrong?: Yes. If the laboratory only checks that semaglutide is present, a vial missing cagrilintide passes. If it checks both, the ratio can still be far from the label, because identity says nothing about amounts. And a third peptide can be present alongside both. Read the report for two masses, two amounts, per-peptide purity and a statement on any other significant peaks.
Is CagriSema an approved medicine?: Published phase 3a trials describe cagrilintide and semaglutide given together as an investigational combination. The US FDA states that cagrilintide is not a component of any FDA-approved drug. Semaglutide on its own is the active ingredient of approved products such as Ozempic. A vial sold as the blend is therefore not an approved product, and only testing shows what it contains.

Sources

Garvey WT et al. Coadministered Cagrilintide and Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2025;393(7):635-647, PubMed
FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss, US Food and Drug Administration
Ashraf AR et al. Multifactor Quality and Safety Analysis of Semaglutide Products Sold by Online Sellers Without a Prescription. J Med Internet Res. 2024;26:e65440, Journal of Medical Internet Research (PMC)
Kopp KL et al. Impurities and Potential Immunogenicity Associated With Follow-on and Compounded GLP-1 Receptor Agonists. Pharm Res. 2026;43(8):2861-2886, Pharmaceutical Research (PMC)
PubChem CID 171397054, Cagrilintide, National Library of Medicine
PubChem CID 56843331, Semaglutide, National Library of Medicine
Ozempic (semaglutide) prescribing information, Novo Nordisk

Last reviewed 6 Oct 2026.