How to read a COA: a 6-point checklist

A certificate of analysis is only useful if it matches the vial in your hand. Before trusting one, check:

1. Batch / lot number — does it match the number printed on your vial? A COA for a different batch tells you nothing about yours.
2. The lab — is a named, independent testing lab on the report, or only the vendor's own letterhead?
3. Date — when was the batch tested? Very old reports on a "fresh" batch are a warning sign.
4. Purity (HPLC) — usually shown as a percentage. Look for the chromatogram, not just a number.
5. Identity (mass spec) — confirms the compound is what it claims to be. Purity without identity only tells you the sample is "pure something".
6. Quantity — the measured mg per vial. A 10 mg vial that tests at 8.6 mg changes every calculation you make.

You can look up batches we've recorded at vialcheck.io/verify — and post a COA here if something doesn't look right. Blur any order or personal details first.