Medutest result on a Shanghai mazdutide lot lands 1.2 points above the supplier’s stated figure

An independent purity determination on mazdutide material sold by SWB has returned 98.6%, a figure 1.2 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 August 2025 and posted unopened.

Content by elemental nitrogen determination returned 94% of the labelled nominal mass, which on a 10 mg vial corresponds to roughly 12.66 mg of peptide rather than the labelled figure. The remainder is accounted for by counter-ion, residual water and residual solvent, none of which is visible chromatographically.

Purity became this trade’s single figure of merit because it is the cheapest measurement to obtain and the easiest to compare. Peptide content, which determines how much drug is actually in a vial, costs several times as much and is quoted as a priced addition by most of the twenty companies in the Journal’s dossier programme rather than carried as a standard release test. Sterility and endotoxin are separate disciplines again, and are neither tested nor claimed.

"Ask for the suitability summary before you argue about the percentage," said Dr Wenjun Xie, process chemist and peptide manufacturing consultant. "If the tailing factor and the replicate precision are outside limits, you are arguing about arithmetic performed on an unfit separation."

SWB’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.