COA Red Flags Checklist
Ten things to check on any Certificate of Analysis before you trust it — free, and delivered to your inbox.
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10 Things to Check on Any COA
General documentation literacy for reviewing a Certificate of Analysis from any research supplier.
1. Lab Name & Accreditation
A real COA identifies the testing lab by name. Look for an independent, accredited lab (for example ISO/IEC 17025) rather than an unnamed or in-house-only lab.
2. Matching Batch/Lot Number
The lot number on the COA should match the lot number printed on your vial or product label. If they do not match, the COA may belong to a different batch entirely.
3. Test Date vs. Manufacture Date
Check that the COA’s test date makes sense relative to when the product was made and shipped to you. A COA dated years before your order is a red flag.
4. Method Disclosed
A credible COA states what method was used (HPLC, LC-MS, NMR, etc.). A purity number with no method or supporting data attached is not verifiable.
5. Identity AND Purity
A complete COA addresses both identity (is this actually the compound it claims to be) and purity (how much of it is that compound). One without the other is incomplete.
6. Compound-Specific Data
The molecular weight, sequence, or compound name on the COA should match the specific product you are viewing, not a generic template reused across the whole catalog.
7. Independently Verifiable
Look for a way to confirm the report is real: a lab website, a batch lookup tool, or contact information for the testing lab itself.
8. Document Quality
Watermarks, mismatched fonts, blurry text, or obvious copy-paste/edit artifacts are signs a document may have been altered.
9. Available Before Purchase
A supplier confident in its documentation will usually share a batch-specific COA when you ask, before you buy — not only after.
10. Consistency Across Batches
Ask what changes (or does not) between batches. A supplier that tests every batch should be able to show you more than one COA on request.
See How the Covered Suppliers Compare
Once you know what to look for, compare what each supplier actually publishes on the Supplier Comparison page, and read real documented experiences in the Supplier Reviews & Experiences forum.
This checklist is general documentation-literacy guidance, not a guarantee of any product’s purity or legitimacy, and not medical or legal advice. Always verify COAs directly with the testing lab where possible. Research Use Only.