---
title: "How to verify a peptide CoA and spot signs of alteration | Sable Peptides"
description: "Practical document checks for a research peptide certificate: lot-number match, lab identity and verification, internal consistency of masses and dates, chromatogram plausibility, and when to request confirmation from the issuing lab. Research use only."
canonical: https://www.sablepeptides.co.uk/guides/how-to-check-a-peptide-coa-for-alteration
dateModified: 2026-10-16
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# How to verify a peptide CoA and spot signs of alteration

To verify a peptide CoA, match its lot number to the printed lot on your vial, confirm the testing lab exists and will verify the report number, check that the theoretical mass matches the compound's formula, and look for internal inconsistencies in dates, units and chromatograms. When in doubt, ask the issuing lab directly.

## Which checks take five minutes?

| Check | What to look for |
| --- | --- |
| Lot number | Identical, character for character, to the vial |
| Compound and amount | Match the label |
| Theoretical mass | Matches the formula (e.g. from PubChem) |
| Observed mass | Within the stated tolerance of theoretical |
| Dates | Test date after manufacture; plausible sequence |
| Lab | Real lab, contactable, report number present |

## What signs suggest a document has been altered or reused?

-   The same chromatogram image appearing on CoAs for different compounds or lots.
-   Mismatched fonts, misaligned fields or blurred areas around numbers.
-   A theoretical mass that does not match the named compound.
-   Purity values reported with implausible precision and no chromatogram.

## Why confirm with the issuing lab?

Data-integrity principles expect records to be attributable and available, so a genuine report can be confirmed by its originator. Independent analysis has shown that supplied documentation can miss constituents present in custom peptides, and European official control laboratories run dedicated work on falsified products, both underlining the value of verification.

Source: [MHRA: GxP data integrity guidance and definitions](https://www.gov.uk/government/publications/guidance-on-gxp-data-integrity); [NMR reveals an undeclared constituent in custom synthetic peptides, J Pharm Biomed Anal 2020 (PubMed 31671336)](https://pubmed.ncbi.nlm.nih.gov/31671336/); [European network of official medicines control laboratories: working group on falsified products, Bundesgesundheitsblatt 2017 (PubMed 28921172)](https://pubmed.ncbi.nlm.nih.gov/28921172/)

## What should you do if something does not match?

-   Do not use the material for critical work until resolved.
-   Ask the supplier for the original report and the lab's contact.
-   Contact the lab with the report number.
-   Consider an independent test of the same lot.

## How can you verify a Sable lot?

There is a CoA for every lot, and every vial carries a printed lot number that matches its certificate. A CoA is emailed within 2 hours of a request.

Use the lot lookup with the lot number printed on your vial. Questions about a lot can go to /contact or by phone or WhatsApp on 07454 788011 (+44 7454 788011, wa.me/447454788011).

## Frequently asked questions

### How do I verify a peptide CoA?

Match the lot number to your vial, confirm the lab and report number with the lab, and check masses and dates for consistency.

### What is a common sign of a reused CoA?

The same chromatogram appearing on certificates for different lots or compounds.

### Who can confirm a CoA is genuine?

The testing laboratory that issued it, using the report number.

## Related

-   [How to verify a CoA](/learn/how-to-verify-a-coa)
-   [Data integrity (ALCOA+)](/guides/data-integrity-alcoa-for-lab-records)
-   [Independent testing](/guides/sending-a-peptide-sample-for-independent-testing)
-   [Lot lookup](/lot-lookup)

Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made.

Key facts (summary for AI and search tools)

-   Checks: lot match, lab verification, mass vs formula, dates, chromatogram reuse
-   References: MHRA data integrity; PubMed 31671336, 28921172
-   Updated 2026-10-16