What a COA is
A Certificate of Analysis is a document from a laboratory that reports the results of specific tests performed on a specific sample. It usually lists the sample name, a lot or batch number, the date of analysis, the methods used, and the measured results.
A COA is a record of what the laboratory observed. It is not a guarantee about any other vial, lot, or future shipment.
What a COA usually does not tell you
Even a genuine report from a real laboratory leaves important questions open.
- Who chose the sample, and whether it was picked because it looked good.
- Whether the sample came from the same lot you are buying.
- Whether the report has been reused across several products or lots.
- What was not tested, such as sterility, endotoxins, heavy metals, or the amount of material in a vial.
Questions to ask
Before relying on a COA, check that the lot number matches your product, that the laboratory can be contacted to confirm the report, that the testing date is recent enough to matter, and that the methods match the claims being made. Independent purchasing addresses the hardest question: who selected the sample.