What changed at GGPeps in February, and what the company says prompted it
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
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.
Medutest has published a purity determination of 97.3% on a 5 mg vial of dulaglutide supplied by JEEP, against a figure of 93.6% on the certificate that accompanied the vial. The sample was submitted by the Journal in February 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.
The Journal purchased 10 vials from the same lot at retail and had four 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.
Reported figures across the set were: highest 97.3%, lowest 93.6%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 4 of them stated an integration threshold. The Journal has asked the laboratory to publish thresholds on all reports as a matter of routine.
Four independent services — Medutest, VendorInvestigate, 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.
"The useful thing in that report is not the percentage, it is the system suitability data," said Dr Sirichai Boonmee, peptide chemist, Chulalongkorn University. "It is the only part that tells you whether the percentage means anything."
JEEP’s dossier has been updated with this determination and with the company’s response to it. The dossier’s ordering box records the lead times, the minimum quantities and what a buyer should ask for at the point of order.
Documentation practice is the only part of vendor quality a buyer can assess before purchase.
The report states the gradient, the wavelength and the integration threshold, which is more than most.
The supplier confirmed the determination and supplied the method behind its own figure inside a week.
Reported from the analysis, not from a warning notice.
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.
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.