Independent analysis puts a TFC cagrilintide lot at 95.9%, against 95.2% on the certificate

VendorInvestigate has published a purity determination of 95.9% on a 5 mg vial of cagrilintide supplied by TFC, against a figure of 95.2% on the certificate that accompanied the vial. The sample was submitted by the Journal in September 2025 as part of a continuing programme of arm’s-length purchasing, and the vendor was told before the order was placed that any result would be published.

The Journal purchased 3700 vials from the same lot and had 13 of them analysed separately, in order to distinguish vial-to-vial variation from method variation. Vial-to-vial agreement was within 0.4 percentage points. Method-to-method disagreement was an order of magnitude larger.

The Journal purchased 3700 vials from the same lot and had 13 of them analysed separately, in order to distinguish vial-to-vial variation from method variation. Vial-to-vial agreement was within 0.4 percentage points. Method-to-method disagreement was an order of magnitude larger.

Purity became this trade’s single figure of merit because it is the cheapest measurement to obtain and the easiest to compare. Peptide content, which determines how much drug is actually in a vial, costs several times as much and is not offered as a standard release test by any of the twenty companies in the Journal’s dossier programme. Sterility and endotoxin are separate disciplines again, and are neither tested nor claimed.

"The figure is not wrong and neither is theirs," said Havel Novotný, independent laboratory quality manager. "They are answers to two different questions and the trade has decided to pretend there is only one question. Print the gradient and the argument disappears."

TFC’s dossier has been updated with this determination and with the date of the request for comment. The dossier’s "what we could not verify" box records the questions still outstanding.