Vol. 3, No. 6 — June 2026Independent since 2024

TheCompound Journal

Reporting on incretins, compounding & the peptide supply chain

A monthly journal of record.
30 issues · 32 contributors
Not medical advice. We sell nothing.

Testing Dispatch

Independent analysis puts a FGP retatrutide lot at 97.1%, against 95.4% on the certificate

The result is unremarkable. What the report omits is not.

Janoshik has released a batch of 7 analytical reports on research-grade retatrutide lots, including material from FGP and SSA. Reported purities range across roughly 4.0 percentage points, and the report set is unusual in stating the analytical method for every determination rather than for some of them.

The Journal purchased 600 vials from the same lot and had 7 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 97.1%, lowest 95.4%, median close to the midpoint of the two. Every report in the set stated a detection wavelength, and 7 of them stated an integration threshold. The Journal has asked the laboratory to publish thresholds on all reports as a matter of routine.

The wider context is that material sold for research use carries no regulatory release specification in any jurisdiction the Journal has examined. A certificate is a commercial document, not a compliance one, and its content is whatever the issuer chooses to put on it. That is the gap independent testing fills, and it fills it imperfectly.

Yusuf Kandemir, freight and customs broker, Istanbul, said the gap was predictable from the methods alone. "You can reconstruct almost the whole difference from the integration threshold. What you cannot reconstruct is why anyone thinks a number without a threshold is comparable to a number with one."

FGP’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.

Related coverage