PeptideMeter result on a Tianjin liraglutide lot lands 4.0 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
Independent testing
Page 5 of 27 of this archive, newest first.
PeptideMeter result on a Changsha retatrutide lot lands 3.4 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
A certificate is a snapshot, and peptides do not stand still
What happens to traceability when bulk material is subdivided, repackaged and relabelled two or three times before sale.
Who signed this, and what did they undertake by signing it
A manufacturer’s certificate is a self-declaration. An accredited laboratory’s report is a third-party measurement. The trade prints both under one heading.
Independent analysis puts a BCH orforglipron lot at 97.2%, against 93.1% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Janoshik result on a Changsha tirzepatide lot lands 0.8 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Independent analysis puts a JEEP mazdutide lot at 98.9%, against 97.7% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Same material, different gradients, different answers
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.
Medutest result on a Shenzhen retatrutide lot lands 2.4 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The badge economy, and what it is actually certifying
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 Xianning survodutide lot lands 4.4 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Reproducibility, measured rather than assumed
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.
Turnaround, cost and accreditation across the services this trade relies on
We asked all four services what they can determine, on what timescale, at what price, and under what accreditation. The answers are printed in full.
Who signed this, and what did they undertake by signing it
Accreditation is granted for a defined scope of methods. A laboratory can be properly accredited and the test on your certificate can sit outside it.
The submitted sample: the weakest link in the whole system
The condition on arrival is recorded by some services and not others, and it is one of the more informative lines in a report.
Why VendorInvestigate can tell you the mass is right and not that the sequence is
The Journal’s standing position: a mass that matches is necessary evidence of identity and nowhere near sufficient.
The badge economy, and what it is actually certifying
Every step between the laboratory report and the product page removes information, and the badge is the last step.
Why TFC can be entirely straightforward and still tell you nothing about bioburden
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.
Repackaging, subdivision, and the batch number that changed hands
A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer than the paperwork admits.
Calibrated, qualified, accredited: three words that are not synonyms
System suitability is the set of checks demonstrating that the instrument and method were performing adequately when your sample was injected. It is recorded as a matter of…