How to Read a Certificate of Analysis
A plain guide to the document that ships with every in-stock lot, and what each part of it actually tells you.
A certificate of analysis, or COA, is the laboratory report that accompanies a research material. It records what a lab found when it tested a specific lot: what the material is, and how pure it is. This page explains what a COA contains and how to read one, so you can confirm exactly what is in a given vial before it reaches the bench. It is written for people evaluating research materials and is not medical guidance.
What a COA is
A COA is a test report tied to a single lot. It is produced by a laboratory that analyzes a sample and documents the results. For research peptides, the two properties that matter most are identity (whether the material is the compound it claims to be) and purity (how much of the sample is that compound, as opposed to everything else). A certificate from an independent, third-party lab carries more weight than one produced in-house, because the party doing the testing is not the party selling the material.
What the testing measures
Two analytical methods do most of the work on a peptide COA.
- Mass spectrometry confirms identity. It measures the molecular weight of the material and compares it against the expected weight for the peptide's sequence. A match is evidence that the vial contains the compound named on the label.
- HPLC (high-performance liquid chromatography) measures purity. It separates a sample into its components and reports the target peptide as a percentage of the whole. A purity figure of, say, 99 percent means that share of the sample is the named compound.
When you read these results, take the numbers exactly as the certificate prints them. A COA is a record of a specific measurement on a specific lot, not a rounded or averaged claim.
Reading the fields
Most peptide certificates share the same handful of fields. Here is what each one tells you.
How to tell a COA is genuine
A certificate is only as useful as your ability to tie it to the vial in your hand. Two checks matter most.
- The lot number on the certificate should match the lot number on the label. If they do not match, the certificate does not describe what you are holding.
- The certificate should be verifiable at its source, not just a PDF that arrived by email. On Vaelith, every lot number can be entered on the verification page, which returns the COA on file for that exact lot. If a number does not resolve, treat that as a reason to ask before you rely on the material.
Why this matters
The usefulness of a research material is bounded by how well its identity and purity are documented. A COA is the record that lets a lab know what it is working with. A verifiable COA is the difference between taking that record on faith and being able to check it against the source, lot by lot.
Frequently asked
What is a Certificate of Analysis?
A laboratory test report tied to a specific lot, documenting a material's identity and purity. For research peptides it usually reports mass spectrometry (identity) and HPLC (purity).
What does HPLC purity mean?
HPLC separates a sample into its parts and reports the target compound as a percentage of the whole. A higher percentage means less of anything else is present.
How do I confirm a COA is genuine?
Match the lot number on the certificate to the label, then confirm it by that number on the verification page rather than trusting a loose file.
Does a COA mean a material is safe to use?
No. A COA documents identity and purity for research purposes only. Vaelith materials are for laboratory research use only and are not approved for human or veterinary use.