Independent analysis puts a FGP tirzepatide lot at 96.0%, against 93.3% on the certificate

An independent purity determination on tirzepatide material sold by FGP has returned 96.0%, a figure 2.8 percentage points above the number printed on the accompanying certificate, which the supplier had reported against a shorter gradient and a tighter threshold. The analysis was performed by Medutest on a vial the Journal bought as an ordinary retail customer in May 2026 and posted unopened.

The Journal purchased 15 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.

The Journal purchased 15 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 — Medutest, VendorInvestigate, 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 useful thing in that report is not the percentage, it is the system suitability data," said Havel Novotný, independent laboratory quality manager. "It is the only part that tells you whether the percentage means anything."

FGP’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.