Independent analysis puts a SSA survodutide lot at 97.1%, against 96.4% on the certificate
The result is unremarkable. What the report omits is not.
Félix Oyarzún
Page 5 of 7 of this archive, newest first.
Archive — page 5
134 piecesMedutest result on a Nantong semaglutide lot lands 3.0 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
At 214 nanometres you see every peptide bond. At 280 you see three residues.
Area per cent silently assumes that every species in the sample absorbs as strongly per unit mass as the parent. For peptide impurities that assumption is usually wrong, and…
What changed after we published the first version of this
A reader holding a certificate can work out what it does not cover in about ninety seconds, and that is a useful ninety seconds.
What the older diet-and-exercise trials found in the hip
Weight loss reduces bone mineral density at load-bearing sites. Whether that translates into fractures in this population is unmeasured.
Independent analysis puts a SGN mazdutide lot at 99.2%, against 96.3% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
The retest date and the expiry date are not the same document
We asked twenty companies three questions about stability data and print every answer, refusal and non-response.
Two sessions a week, and the evidence behind the prescription
The recommendation survives scrutiny. The reasoning offered for it frequently does not.
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.
Independent analysis puts a QST dulaglutide lot at 95.3%, against 91.7% on the certificate
The result is unremarkable. What the report omits is not.
Medutest result on a Suzhou tirzepatide lot lands 2.9 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
The certificate is silent on contamination, and it never claimed otherwise
Every certificate circulating in this market answers a question about molecules. Almost none answers a question about organisms, pyrogens, or the integrity of the seal.
D-amino acids are invisible to mass spectrometry, and that is the whole problem
Stereochemical inversion changes the molecule, changes its biology, and changes its mass by exactly nothing.
Custody, condition and the temperature nobody logged
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.
Independent analysis puts a Homopeptide orforglipron lot at 99.1%, against 98.4% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
What the trials monitored, and what that implies about routine practice
Timing is the whole of the post-cessation panel: draw it too early and it measures the treatment period.
What the trials monitored, and what that implies about routine practice
Timing is the whole of the post-cessation panel: draw it too early and it measures the treatment period.
VendorInvestigate result on a Suzhou liraglutide lot lands 4.2 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
Peak capacity, and the honest measure of a separation
Column chemistry, particle size and pore diameter determine what the separation is capable of before the gradient is even programmed.
PeptideMeter result on a Guangzhou cagrilintide lot lands 3.7 points below the supplier’s figure
The result is unremarkable. What the report omits is not.