The cake is a record of the cycle that made it
Lyophilisation does not stop degradation. It slows every pathway by removing the solvent that most of them require, and the residue of solvent that remains sets the rate.
Callum Brathwaite
Page 6 of 7 of this archive, newest first.
Archive — page 6
134 piecesPeptideMeter result on a Suzhou retatrutide lot lands 2.2 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
Glass, elastomer, aluminium: a three-material argument about one closure
Particulate matter is the oldest quality attribute in injectable manufacture and the one a private buyer is best placed to assess without instrumentation.
The out-of-range flag is a statistical convention with a printer attached
Almost every misreading of a laboratory panel is a misunderstanding of what a reference interval is and how much a result has to move before the movement means anything.
Reading a barrel in the wrong increments
We have catalogued what readers report, ranked by the size of the dosing error each produces.
Independent analysis puts a CPC orforglipron lot at 96.1%, against 94.6% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
PeptideMeter result on a Tianjin mazdutide lot lands 4.3 points below the supplier’s figure
The supplier has not disputed the finding. It has not explained the gap either.
Four ways a peptide comes apart
We describe each pathway in enough chemical detail to explain why it is invisible to the method the trade uses, because that is the part which has practical consequences.
What VendorInvestigate is able to certify about a sealed vial, and what it is not
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 QST cagrilintide lot at 98.4%, against 96.0% on the certificate
The supplier has not disputed the finding. It has not explained the gap either.
Quadrupole, time-of-flight, orbital trap: what each class can and cannot see
Every instrument specification quoted in an advertisement is a best case obtained on a calibration mixture, not on a submitted vial.
What the paperwork is for, and who it was designed to protect
The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are usually incomplete.
What a laboratory knows about the material it receives
Chain of custody, in a regulated setting, begins at sampling. Here it begins when the package arrives.
Janoshik result on a Suzhou tirzepatide lot lands 4.1 points below the supplier’s figure
The result is unremarkable. What the report omits is not.
Bone density during rapid weight loss: what is known, which is less than you would hope
Weight loss reduces bone mineral density at load-bearing sites. Whether that translates into fractures in this population is unmeasured.
VendorInvestigate result on a Zhuhai survodutide lot lands 0.9 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
The number at the bottom of the certificate
A purity percentage is the most quoted figure in the research-peptide trade and one of the least examined. We asked four laboratories to analyse the same vial and got four…
Twenty-eight days is a number from somebody else’s product
We set out what is known, what is inferred and what is simply assumed about the fortnight after a vial is opened.
Independent analysis puts a WXT semaglutide lot at 98.0%, against 95.7% on the certificate
The result is unremarkable. What the report omits is not.
Independent analysis puts a GL Biochem tirzepatide lot at 96.7%, against 95.9% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.