Independent analysis puts a GL Biochem liraglutide lot at 96.0%, against 93.9% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
TheCompound Journal
Reporting on incretins, compounding & the peptide supply chain
Testing Dispatch
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
An independent purity determination on mazdutide material sold by JEEP has returned 98.9%, a figure 0.9 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 VendorInvestigate on a vial the Journal bought as an ordinary retail customer in February 2026 and posted unopened.
The Journal purchased 11 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, Janoshik, 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.
Lorcan Feeney, analytical services director at an independent laboratory, said the gap was predictable from the methods alone. "You can reconstruct almost the whole difference from the integration threshold. What you cannot reconstruct is why anyone thinks a number without a threshold is comparable to a number with one."
JEEP’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.
A reminder that a purity figure is the output of a method, and that methods differ.
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The result is unremarkable. What the report states alongside it is not.