Fake peptide COA red flags

Most problem COAs in the UK research peptide market are not elaborate forgeries. They are borrowed, recycled, cropped, or assembled from a genuine template with numbers typed in. That makes them easy to catch if you know the fifteen or so tells that recur. This note is a checklist for the two minutes between receiving a certificate and deciding whether to trust it. All Alphex products are for laboratory and in-vitro research only.

This is the checklist version. The full guide to reading a certificate is how to read a research peptide COA; use this page when you have a document in front of you and two minutes.

Document-level flags

1. No issuing laboratory named, or a name with no findable address, website or accreditation.
2. No report reference number.
3. No batch number, or a batch number that does not appear on the vial. See batch matching.
4. No test date, a date before the product existed, or a date years old for a compound the supplier restocks regularly.
5. The same document supplied for different batches, or the same batch number for a year.
6. Inconsistent fonts, alignment or resolution in the results table, suggesting figures were edited into a template.
7. A stated purity but no chromatogram, or a stated identity but no mass.

Chromatogram flags

8. No axes, units or integration table. A picture of a peak is not data.
9. The integration table does not sum to 100%, or the visible minor peaks do not match the stated impurity total.
10. A single perfect peak, flat baseline, no solvent front, especially for a large peptide where minor species are expected.
11. The sample name on the trace does not match the COA header (different batch, different compound, or a generic name).
12. The identical trace appears on COAs for different batches or compounds. Compare retention time and peak shape.
13. Purity reported at 280 nm only for a peptide with few aromatic residues. See 220 nm versus 280 nm.

Mass-spectrum flags

14. "Identity: conforms" with no observed mass.
15. Observed mass identical to theoretical to four decimals across several batches; real measurements vary slightly.
16. A single peak at the full molecular weight for a large peptide with no charge-state envelope. See mass spectrometry explained.
17. The wrong compound's mass, such as full-length thymosin beta-4 on a TB-500 certificate.

Contextual flags

• Every compound in the catalogue at exactly the same purity figure.
• The supplier cannot say whether the COA is manufacturer QC or independent. See third-party versus in-house testing.
• The supplier will only send the COA after purchase.
• The supplier objects to you contacting the laboratory. See how to verify a COA with the lab.

What a clean certificate looks like

Named independent laboratory with report reference and date; batch number matching the vial and appearing on the trace; chromatogram at 220 nm with axes, method, integration table and resolved minor peaks; ESI-MS with theoretical and observed mass and the spectrum; salt form stated; and a supplier willing to send it before purchase. That is what an Alphex COA contains, and you can see one for the current batch of any product via the COA request form. The fuller reading guide is how to read a research peptide COA.

Alphex research peptides are supplied for laboratory and in-vitro research by qualified researchers only. They are not authorised for human or veterinary use.

Research use only. Alphex products are supplied exclusively for laboratory and in-vitro research by qualified researchers. They are not authorised for human or veterinary use, and nothing in this note is advice on any such use.

Published 9 July 2026, last reviewed 16 August 2026. Alphex reviews research notes when the testing method, the catalogue or UK guidance changes.

Alphex Research Team

Alphex Limited, UK research peptide supplier

The Alphex research team writes and maintains these notes for UK laboratories buying research peptides. Every batch Alphex lists is verified by reverse-phase HPLC with a batch-matched Certificate of Analysis. Content covers laboratory and in-vitro research only.