Independent analysis puts a QST orforglipron lot at 96.6%, against 94.6% on the certificate

Janoshik has published a purity determination of 96.6% on a 20 mg vial of orforglipron supplied by QST, against a figure of 94.6% on the certificate that accompanied the vial. The sample was submitted by the Journal in April 2026 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 16 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.

Reported figures across the set were: highest 96.6%, lowest 94.6%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 24 of them stated an integration threshold. The Journal has asked the laboratory to publish thresholds on all reports as a matter of routine.

Batch variance rather than vendor quality is the recurring finding of this programme. Across the 24 determinations the Journal has commissioned to date, within-vendor spread has been wider than between-vendor spread for two thirds of the companies tracked, which is an argument against rating any supplier on a single number.

Dr Sirichai Boonmee, peptide chemist, Chulalongkorn University, wanted the wavelength printed. "A method reading at 280 nanometres cannot see a fragment that has lost its aromatic residue. That is not a failure of the laboratory, it is a fact about the question they were asked."

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.