Two sessions a week, and the evidence behind the prescription
One randomised trial has combined a GLP-1 receptor agonist with supervised exercise. Its result is the single most useful piece of evidence in this area.
Recent work
134 piecesThe convention nobody explains before handing over the vial
Insulin syringes are graduated in units on a convention that fixes 100 units to one millilitre. That convention says nothing about how much peptide is in a unit, and…
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.
Independent analysis puts a QYB mazdutide lot at 95.3%, against 92.9% on the certificate
The result is unremarkable. What the report omits is not.
The word “confirmed” is doing an enormous amount of work on this certificate
The Journal’s standing position: a mass that matches is necessary evidence of identity and nowhere near sufficient.
What we asked twenty suppliers about stability data
We asked twenty companies three questions about stability data and print every answer, refusal and non-response.
Independent analysis puts a FGP tirzepatide lot at 96.0%, against 93.3% on the certificate
The result is unremarkable. What the report omits is not.
An error taxonomy for a market without a pharmacist
The recurring errors in this market are not exotic. They are a small set of arithmetic and reading failures, each capable of moving a dose by a factor of two or ten.
Carbon-13, and the reason a peptide has more than one mass
A peptide has a monoisotopic mass and an average mass, they differ by several daltons at this molecular size, and a certificate that does not say which it quotes cannot be…
We asked four laboratories for a sterility test. Here is what came back.
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.
PeptideMeter result on a Changsha orforglipron lot lands 1.7 points below the supplier’s figure
The report states the gradient, the wavelength and the integration threshold, which is more than most.
PeptideMeter result on a Changsha mazdutide lot lands 1.3 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure
We submitted vials for endotoxin determination and report the results, the method and the laboratory, because a pyrogen figure without a method is as empty as a purity…
Janoshik result on a Zhuhai tirzepatide lot lands 2.5 points below the supplier’s figure
A reminder that a purity figure is the output of a method, and that methods differ.
What orthogonal actually means, and what it does not
The most useful single addition to any purity determination is a second separation under a different pH or on a different stationary phase, and the second-most useful is a…
Independent analysis puts a MKM liraglutide lot at 99.0%, against 97.4% on the certificate
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
VendorInvestigate result on a Chengdu tirzepatide lot lands 3.4 points below the supplier’s figure
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Sterility is not a percentage, which is the whole difficulty
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.
Counter-ion, water, salt: three masses with no chromatogram
Aggregates dissociate in the mobile phase and are recorded as monomer. Only a size-based separation reports them.
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.