Free lab-report guide
A COA can say 99% and still leave out important details.
A Certificate of Analysis, or COA, is a lab report. Use these five checks to see which sample was tested, who tested it, how it was tested, and what the result does not tell you.
Educational only. This page contains no seller links or product recommendation.
Who does what?
Vendor, laboratory, and COA are three different things.
The vendor
Sells the product, identifies the lot, arranges testing, and chooses which reports to publish.
The laboratory
Tests the sample it receives using the methods listed on its report. The report should identify the lab and its results.
The COA
Connects that submitted sample to the named tests and results. Your first job is matching it to the exact lot you are checking.
A useful vendor makes the lot match easy, publishes complete lab-original reports, and gives you enough information to verify the laboratory independently.
The 60-second map
Know what each word is trying to answer.
Is this the compound named on the report?
How much of the compound did the test measure?
How much of the detected material appears as the main compound rather than related impurities?
Did the named test detect viable microorganisms under its stated conditions?
Did the named test measure bacterial endotoxin below the report's stated limit?
Which specific group of product the submitted sample is meant to represent.
Easy rule: one test does not answer every question. A purity result is not the same as identity, quantity, sterility, or endotoxin.
The five checks
Read the report in this order.
What sample was tested?
Look for a report number, lot or batch identifier, sample description, and dates. A report that cannot be tied to a specific sample cannot establish what is in another item.
Can I match this report to the exact lot?Which method answered which question?
Identity and purity are different questions. The report should name the method used for each result instead of presenting one unexplained percentage.
Is the method named beside the result?Can the laboratory be verified?
Confirm that the laboratory exists independently of the seller. If accreditation is claimed, verify the credential and whether its scope covers the method on the report.
Did I verify the lab outside the seller's website?What does the result not prove?
A purity percentage does not automatically establish quantity, sterility, endotoxin status, stability, safety, or effectiveness. Those require different evidence.
Am I reading more into the number than it says?Is the underlying data present?
A summary table is easier to fake or misunderstand than a complete report. Look for named methods, units, signatures, dates, and the lab's underlying graph or spectrum when applicable.
Is this a complete report or only a marketing summary?A report can reduce uncertainty. It cannot remove it.
Even a complete laboratory report describes the submitted sample and the tests that were actually performed. It does not establish that every other item is identical, or answer questions outside the report’s scope.
Source notes