How RETA UK Quality-Tests Research Peptides

At RETA UK, peptide quality assurance is not an afterthought — it is an operational gate that every batch of research compounds has to pass before it can be sold. No batch reaches a UK researcher until it has been independently analysed by an accredited third-party laboratory and reviewed against our internal acceptance criteria. This page explains that workflow in detail; the verified certificates themselves are published on our COA page.

The three pillars of our testing

The end-to-end testing workflow

This is the exact sequence every batch follows from the moment it arrives at our UK warehouse:

1. Intake & loggingThe batch is received and logged against a unique internal batch ID (for example EGB-0126-TR40) so it can be traced from arrival through to sale.
2. Quarantine holdThe stock is placed in a non-sellable quarantine status. It cannot be added to inventory, picked or shipped while it is awaiting results.
3. Representative sampling & sealingRepresentative vials are pulled from the batch, sealed, and prepared for dispatch under chain of custody so the sample tested is genuinely from the lot we received.
4. Independent third-party analysisSamples are sent to an accredited laboratory (Janoshik Analytical or Analiza Białek) for HPLC purity quantification and mass spectrometry identity confirmation.
5. Review against acceptance criteriaOur team reviews the returned data against fixed criteria — percentage purity, correct molecular weight and identity, and related substances within limits — before any decision is made.
6. Release or rejectA batch that meets every criterion has its Certificate of Analysis published on the COA page and is released for sale. A batch that fails is rejected and never offered to researchers.

Analytical methods we rely on

• HPLC (High-Performance Liquid Chromatography) — quantifies percentage purity and detects related substances or degradation products in the sample.
• Mass spectrometry — verifies the molecular weight of the compound and provides unequivocal identity confirmation, so you know the vial contains the peptide it claims to.
• Supplementary assays — additional analytical methods are commissioned where a compound's profile demands further validation.

Acceptance criteria & release decision

A Certificate of Analysis on its own is not enough — the numbers have to clear our thresholds. Before a batch is released we require:

• Purity — HPLC purity at our target threshold (typically ≥ 99%) across the tested vials.
• Identity — mass spectrometry confirming the correct molecular weight for the declared compound.
• Related substances — impurities and degradation products within acceptable limits.

If any criterion is not met, the batch stays in quarantine and is rejected — it is never sold to make up stock. This is why the certificate you see always corresponds to the exact lot currently in circulation, and never to a previous batch.