PeptideMeter result on a Qingdao cagrilintide lot lands 2.2 points below the supplier’s figure

An independent purity determination on cagrilintide material sold by HJ has returned 95.3%, a figure 2.2 percentage points below the number printed on the accompanying certificate. The analysis was performed by PeptideMeter on a vial the Journal bought as an ordinary retail customer in February 2024 and posted unopened.

Reported figures across the set were: highest 95.3%, lowest 92.4%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 9 of them stated an integration threshold. The Journal has asked the laboratory to publish thresholds on all reports as a matter of routine.

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 Rowena Ashcombe, community pharmacist and diabetes educator. "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."

HJ’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.