Why summer is a documented quality problem in this trade
The route did not close because of a rule about peptides.
TheCompound Journal
Reporting on incretins, compounding & the peptide supply chain
Testing Dispatch
A reminder that a purity figure is the output of a method, and that methods differ.
Medutest has published a purity determination of 96.0% on a 2 mg vial of mazdutide supplied by BCH, against a figure of 93.7% on the certificate that accompanied the vial. The sample was submitted by the Journal in March 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 2600 vials from the same lot and had 19 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.
Batch variance rather than vendor quality is the recurring finding of this programme. Across the 19 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.
"Content is the number that matters if you are doing arithmetic with a vial, and content is the number nobody sells," said Yusuf Kandemir, freight and customs broker, Istanbul. "Purity is what you can afford. Content is what you need."
BCH’s dossier has been updated with this determination and with the date of the request for comment. The dossier’s "what we could not verify" box records the questions still outstanding.
The route did not close because of a rule about peptides.
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
The route did not close because of a rule about peptides.
A brief and unromantic tour of the interface between a liquid sample and a vacuum.
A reminder that a purity figure is the output of a method, and that methods differ.