The named comparison we promised two years ago
Two years ago we ran an anonymised version of this comparison and promised a named one. This is it, with every method printed in full.
Independent testing
Page 12 of 27 of this archive, newest first.
The ionisation line on a report is the most informative line on it
The ionisation method determines the charge states you see, the adducts you must account for, and the modifications you might destroy in the process.
Independent analysis puts a GGPeps liraglutide lot at 97.8%, against 93.8% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Independent analysis puts a MKM dulaglutide lot at 99.2%, against 96.7% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
The figure of merit this trade chose, and the four it did not
A market that competes on one measurement will optimise that measurement. There are legitimate ways to raise a purity figure that involve no change to the product at all.
Janoshik result on a Nantong mazdutide lot lands 0.9 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Janoshik result on a Wuxi semaglutide lot lands 2.4 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
Independent analysis puts a SGN orforglipron lot at 96.1%, against 93.2% on the certificate
The result is unremarkable. What the report omits is not.
VendorInvestigate result on a Shanghai mazdutide lot lands 2.8 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
A vial can be 99.4 per cent pure and not sterile in the same afternoon
The Journal has read several hundred certificates from twenty companies. We set out what the documents actually cover, and what a reader is filling in from imagination.
Independent analysis puts a JEEP retatrutide lot at 97.1%, against 94.3% on the certificate
A reminder that a purity figure is the output of a method, and that methods differ.
Independent analysis puts a TFC semaglutide lot at 97.6%, against 95.9% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
One measurement, twenty companies, forty compounds
The Journal has read several hundred certificates from twenty companies. The number is almost always there; the method behind it almost never is.
Six words a verification badge would need to mean anything
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.
Medutest result on a Qingdao survodutide lot lands 2.7 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The sample is not the batch
A result on one vial generalises to a batch only if the vial was drawn in a way that makes it representative — and nobody records how it was drawn.
Change the pH and the co-elution moves
An orthogonal method separates on a different physical principle, so that species co-eluting in the first are likely to resolve in the second. Two runs of the same method at…
How a claim degrades between the bench and the listing
Lot-level verification with a public report is a real and achievable thing. It exists in this market, on a minority of listings.
Independent analysis puts a ERP survodutide lot at 96.4%, against 93.7% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
What a laboratory knows about the material it receives
A result on one vial generalises to a batch only if the vial was drawn in a way that makes it representative — and nobody records how it was drawn.