Independent analysis puts a QST semaglutide lot at 98.4%, against 97.6% on the certificate

Two laboratories analysing vials from the same semaglutide lot have returned figures 0.9 percentage points apart. VendorInvestigate reported 98.4%; Medutest reported a lower number on a shallower gradient with a tighter integration threshold. Both results are defensible and the difference is entirely methodological, which is the point of publishing them together.

The Journal purchased 12 vials from the same lot at retail and had four 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.

Four independent services — VendorInvestigate, Medutest, and the two others operating in this market — carry the analytical burden for a trade that has no release-testing obligation of its own. Each is paid by whoever submits the sample, which is usually the vendor. The Journal’s position is that a submitter-pays model is workable but that its incentive structure has to be stated whenever a result is quoted as verification.

"The gap that matters is not between the two laboratories, it is between either of them and the certificate," said Lorcan Feeney, analytical services director at an independent laboratory. "One of those documents states a method. Compare like with like and most of this disappears."

QST’s dossier has been updated with this determination and with the company’s response to it. The dossier’s ordering box records the lead times, the minimum quantities and what a buyer should ask for at the point of order.