What a certificate of analysis is
A certificate of analysis, or COA, is a laboratory’s report on one tested sample. It describes that lot as tested, and nothing else. A certificate for a different lot, even of the same compound, tells you nothing about the material in front of you.
So the first thing to check is not the purity figure. It is whether the report belongs to what you received.
The details that identify the sample
- Compound. What the sample was submitted as.
- Lot number. The batch the sample came from. It should match the lot number on your vial or your order exactly.
- Dates. When the lab received the sample, tested it and issued the report.
- Laboratory. Who did the testing, and the client they tested for.
- A verification code. Many labs print a code you can enter on their own website to pull up the original report.
Purity
Purity is usually reported as a percentage measured by HPLC. It is the main compound’s share of everything the instrument detected in the sample. A higher figure means fewer other substances showed up alongside it.
Purity is not the same as the amount of peptide in the vial. A freeze dried sample also holds water and salts that HPLC does not count. Some reports state the peptide content or quantity separately. If yours does not, the purity figure says nothing about quantity.
Identity
Identity answers a different question: is the main compound the one on the label? It is usually confirmed by mass spectrometry, which measures the mass of the molecules in the sample and compares it with the compound’s expected mass. A report should show both the expected and the observed value.
Purity on its own cannot confirm identity. The wrong compound can still produce a clean result. That is why a useful certificate reports both. Our guide to HPLC and mass spectrometry explains each test.
How to confirm a certificate at the source
A certificate that a seller hosts is only a picture until the laboratory confirms it. To check one:
- Copy the verification code printed on the certificate.
- Open the laboratory’s own lookup page. Go to the lab’s website yourself, not through a link on the seller’s site.
- Enter the code and compare the compound, lot number, purity and dates with the copy you were given.
Every certificate Method Biolabs publishes carries Freedom Diagnostics’ own search code, shown on the certificate card and the lot page with a copy button. If anything on the lab’s record differs from ours, email us and we will explain or correct it in public.
This guide explains how to check documentation. It is not advice on using any product. Method Biolabs supplies reference materials for laboratory research only: not for human or veterinary use, and no dosing or protocol guidance.
