# How to read a certificate of analysis | Peps for Pups

> What a certificate of analysis shows, the terms you will see on one, and the checks worth making before you trust it.

Source: https://pepsforpups.co.uk/learn/how-to-read-a-certificate-of-analysis
Publisher: Peps for Pups (https://pepsforpups.co.uk)
Last updated: 2026-11-13

A certificate of analysis, often shortened to CoA, is a laboratory report on a specific batch. It is the single most useful document a peptide supplier can show you.

## What it should contain

- **The compound name** and the batch or lot number.
- **The testing laboratory** and the date of the test.
- **Identity**, usually confirmed by mass spectrometry. The measured mass should match the expected mass of the peptide.
- **Purity**, usually measured by HPLC and given as a percentage.
- **Content**, the amount of peptide in the vial.

Some reports also include endotoxin or sterility results.

## Terms you will see

- **HPLC**: high performance liquid chromatography. It separates what is in the sample so purity can be measured.
- **MS**: mass spectrometry. It confirms the compound is what the label says.
- **Lot or batch number**: the code that ties a certificate to a production run.

## Five checks worth making

1. Does the batch number on the certificate match the one on your vial?
2. Is the laboratory named, and is it independent of the seller?
3. Is the test dated recently?
4. Can you verify the report with the laboratory, for example through a report code?
5. Does the certificate show the actual data, not only a headline figure?

## Red flags

- A certificate with no batch number.
- The same certificate used for years.
- A purity figure quoted on a website with no document behind it.
- A supplier who will not share the report.

## Our certificates

We publish batch documentation on our [certificates page](/certificates). If a certificate is not yet available for a batch, we say so there.

---
BPC-157 is supplied for research use only. It is not a veterinary medicine and is not for human or animal consumption.