A certificate of analysis, or COA, reports defined test results for a specific material or batch. Start by matching the product and batch, then read the test, method, unit, specification and result together. A COA is evidence within its stated scope, not proof of a health outcome.
Key takeaways
- Match the document to the exact product and batch.
- Check whether the tested material is an ingredient or finished product.
- Specifications and measured results are not the same thing.
- Missing tests cannot be treated as passing tests.
- A certificate does not establish clinical benefit or suitability for every person.
1. Identify the tested item
Look for the product name, material, batch or lot identifier and report date. Confirm that these match the product you are evaluating. A supplier ingredient certificate can describe a raw material without answering every question about the finished pen.
2. Identify who performed the test
Check the laboratory’s legal name and its relationship to the seller or manufacturer. If accreditation is mentioned, verify what entity, method and scope it covers. A logo alone does not prove that every result in the document is accredited.
3. Read each row as a unit
| Field | Question to ask |
|---|---|
| Test | What property was measured? |
| Method | How was it measured? |
| Unit | What scale does the number use? |
| Specification | What acceptance criterion applies? |
| Result | What was actually measured? |
| Date | Which report and batch timeframe does this belong to? |
Identity, potency and purity are different
Identity asks whether the material is what it is claimed to be. Potency or assay asks how much of a named substance is present under the stated method. Purity concerns the composition or specified impurities. One type of result should not be used as shorthand for all three.
What sterility and endotoxin results mean
When present, these tests address specific microbiological attributes under named methods and limits. Their presence must be checked against the tested material and batch. Do not infer them from a purity percentage or from a certificate that does not list them.
Common red flags
- No product or batch identifier.
- A generic example presented as the document for your order.
- A result without units, method or acceptance criterion.
- An ingredient report used as proof of every finished-product attribute.
- Marketing claims that go beyond the tests shown.
- An unreadable or altered document with no way to verify it.
What a COA cannot tell you
A COA does not establish clinical efficacy, an individual response, an optimal amount or legal status in every market. It also cannot prove attributes that were not tested. Quality evidence is one part of a product decision, alongside instructions, safety, storage and support.
Next step: visit NAD.Power quality and batch information to learn how to request the relevant available document for your order.