By the Sequora Research Team · Published October 22, 2026
On October 14, 2026, the UK Medicines and Healthcare products Regulatory Agency (MHRA) and West Midlands Police seized more than 12,000 fake pens labelled as retatrutide and tirzepatide from an industrial unit in Birmingham, along with packaging for around 30,000 more products. The MHRA valued the seizure at about £2 million and said the products had never been checked for quality or contents (MHRA press release). It was the agency’s third such operation in a year, after a February 2026 seizure and the dismantling of an illicit production site in October 2025.
The case is a reminder of a basic point for any laboratory: a label tells you what a product claims to be, not what it is. Only analytical testing of the specific batch can confirm identity and purity. This guide explains how that testing works and how to check it yourself.
Why a label is not evidence
Counterfeit and substandard material can contain the wrong compound, a lower amount than stated, synthesis by-products, or nothing active at all. Packaging, printing and even a document that looks like a certificate can be copied. What cannot easily be faked is a verifiable test result tied to the exact batch in your hands, from a laboratory you can identify.
How HPLC confirms purity
High-performance liquid chromatography (HPLC), usually reversed-phase, separates the components of a sample as they pass through a column. Each component leaves the column at a characteristic time and appears as a peak on a chromatogram. Purity is reported as the main peak’s share of the total peak area.
- Look for the chromatogram itself, not just a percentage.
- Check that one dominant peak accounts for the reported purity, and note any secondary peaks.
- Confirm the method details (column, gradient, detection wavelength) are stated.
How mass spectrometry confirms identity
HPLC shows how pure a sample is, but not what the main component is. Mass spectrometry (MS) measures the molecular mass of what is present and compares it with the theoretical mass of the stated sequence. A match confirms the compound is the one on the label. A mismatch, or a missing MS result, is a warning sign even when the HPLC purity looks high.
How to read a COA in five checks
- Batch number matches the number printed on your vial.
- Compound and amount match the label, including the stated vial content.
- HPLC result is shown with its chromatogram and method.
- MS result reports a measured mass that matches the theoretical mass.
- Testing laboratory and date are identified, so the document can be traced.
Our guide How to Read a Peptide COA walks through a full certificate section by section, and Quality & Testing explains the standard every Sequora batch must meet.
Batch numbers and chain of custody
A batch number links three things: the synthesis lot, the test results, and the vial that reaches your bench. When that link is kept intact, the COA describes the material you actually received. When it breaks, for example when one generic certificate is reused across many lots, the document stops meaning anything for your sample.
At Sequora, each vial label carries its batch number, and each batch has its own certificate from third-party HPLC and MS testing. Specifications on every product page (sequence, formula, molecular weight, CAS number) are cross-checked against public databases, as described in Research Sources & Editorial Standards. If you want the certificate for a batch before ordering, contact us with the product name.
Further reading: how to verify high-purity research peptides · how lyophilized peptides are made and stored · what bacteriostatic water is and what it contains
Sources
- Medicines and Healthcare products Regulatory Agency. Press release on the October 14, 2026 Birmingham seizure, with West Midlands Police. GOV.UK, October 2026. gov.uk
This article is about analytical verification of research materials. It does not describe any use of the compounds named.
For laboratory research use only. Not for human or veterinary use.