VendorInvestigate result on a Shenzhen semaglutide lot lands 1.1 points above the supplier’s stated figure

An independent purity determination on semaglutide material sold by HJ has returned 99.0%, a figure 1.1 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 June 2025 and posted unopened.

Reported figures across the set were: highest 99.0%, lowest 95.3%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 10 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 10 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 Emiko Tanabe, mass spectrometrist, thought the split-sample design was the useful part. "A single result on a single vial is an anecdote with a decimal point. Pairs from one lot to two laboratories is the cheapest experiment that answers a real question."

HJ’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.