How a claim degrades between the bench and the listing
A badge asserts that something was tested. It does not assert what, when, on whose sample, by what method, or whether the lot on sale is the lot that was tested.
TheCompound Journal
Reporting on incretins, compounding & the peptide supply chain
Testing Dispatch
The result is unremarkable. What the report omits is not.
An independent purity determination on orforglipron material sold by ERP has returned 98.6%, a figure 2.4 percentage points below the number printed on the accompanying certificate. The analysis was performed by VendorInvestigate on a vial the Journal bought as an ordinary retail customer in May 2026 and posted unopened.
The Journal purchased 500 vials from the same lot and had 4 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.
Discrepancies of one to two percentage points between a supplier’s figure and an independent determination are common and usually explicable: a faster gradient resolves fewer impurities, a higher integration threshold discards more small peaks, and a wider solvent-front exclusion window removes early-eluting fragments from the calculation altogether. None of that is misconduct. All of it is invisible unless the method is disclosed.
"The useful thing in that report is not the percentage, it is the system suitability data," said Havel Novotný, independent laboratory quality manager. "It is the only part that tells you whether the percentage means anything."
ERP’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.
A badge asserts that something was tested. It does not assert what, when, on whose sample, by what method, or whether the lot on sale is the lot that was tested.
The route did not close because of a rule about peptides.
Purity, content, identity, sterility and endotoxin are five separate determinations. A single sheet of paper carrying one of them is not evidence about the other four.
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.