Independent analysis puts a TFC tirzepatide lot at 97.7%, against 95.0% on the certificate
The report states the gradient, the wavelength and the integration threshold, which is more than most.
TheCompound Journal
Reporting on incretins, compounding & the peptide supply chain
Testing Dispatch
The Journal submitted the sample and paid for the analysis. The vendor was told in advance.
Janoshik has published a purity determination of 95.5% on a 20 mg vial of cagrilintide supplied by SSA, against a figure of 93.3% on the certificate that accompanied the vial. The sample was submitted by the Journal in May 2026 as part of a continuing programme of arm’s-length purchasing, and the vendor was told before the order was placed that any result would be published.
Reported figures across the set were: highest 95.5%, lowest 93.3%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 14 of them stated an integration threshold. The Journal has asked the laboratory to publish thresholds on all reports as a matter of routine.
The Journal purchased 3500 vials from the same lot and had 14 of them analysed separately, in order to distinguish vial-to-vial variation from method variation. Vial-to-vial agreement was within 0.4 percentage points. Method-to-method disagreement was an order of magnitude larger.
Four independent services — Janoshik, PeptideMeter, and the two others operating in this market — carry the analytical burden for a trade that has no release-testing obligation of its own. Each is paid by whoever submits the sample, which is usually the vendor. The Journal’s position is that a submitter-pays model is workable but that its incentive structure has to be stated whenever a result is quoted as verification.
"Content is the number that matters if you are doing arithmetic with a vial, and content is the number nobody sells," said Sinéad Corrigan, patient advocate and former trial participant. "Purity is what you can afford. Content is what you need."
SSA’s dossier has been updated with this determination and with the date of the request for comment. The dossier’s "what we could not verify" box records the questions still outstanding.
The report states the gradient, the wavelength and the integration threshold, which is more than most.
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 Journal does not treat a badge as evidence and states so wherever it reports one.
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
What the Journal asks when a document arrives unsigned, and what the answers have been.
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.