The practical answer
Review a COA against the material actually received and your approved specification. Confirm lot identity, revision, methods, units, result basis and release status. A COA supports a quality decision; it does not automatically replace the manufacturer’s required verification or supplier-qualification process.
First reconcile the documents
Place the purchase order, approved specification, container labels and COA side by side. The product name, grade, manufacturer or authorized supply chain and lot identifiers should connect without unexplained substitutions. A distributor’s reference number may differ from the manufacturer’s number, but the relationship needs to be traceable.
Check the document revision and dates. A generic technical sheet is not a lot result. An unsigned template, an example COA and a released lot certificate have different purposes. Ask for clarification when a document does not state which it is; do not silently promote a sales attachment into a release record.
Then review the analytical meaning
A result such as “complies” may be meaningful for a qualitative identity test. For an important quantitative attribute, a numerical result usually enables better trending and investigation. If the supplier reports “not detected,” ask for the applicable detection or reporting limit before treating it as below your acceptance limit.
| COA field | Receiving review |
|---|---|
| Identity | Method and result refer to the approved material definition |
| Magnesium assay | Actual value, units and as-received or corrected basis are clear |
| Contaminants | Named analytes, relevant limits and adequate reporting capability |
| Microbiology | Count units or organism absence with defined test quantity |
| Water or drying loss | Method and conditions match the specification |
| Disposition | Release authorization and unresolved exceptions are visible |
On smaller screens, scroll the table horizontally.
Resolve exceptions without losing traceability
For example, a dry-basis assay should not be copied into a formulation sheet that assumes an as-received value. A changed unit can be corrected mathematically only when the underlying quantity and basis are the same. If they are not, the laboratory must resolve the difference.
- List each mismatch and the decision it prevents; separate clerical correction from analytical uncertainty.
- Keep the material under the site’s appropriate status while the responsible quality team reviews the issue.
- Obtain a controlled correction or supporting laboratory explanation linked to the original report.
- Retain both the original and revised document, with the reason for the change.
- Record the final disposition and the identity of the person authorized to make it.
Understand the COA’s role
FDA’s dietary-supplement CGMP guidance explains that reliance on supplier COAs for certain specifications is conditional, including supplier qualification. Dietary-ingredient identity verification has separate requirements. A purchasing checklist should support, rather than bypass, the manufacturer’s quality system. [1]
An approved COA review also creates a useful future comparison. Track selected actual results across lots, while keeping specification changes visible. Unexpected trends can justify a discussion before a result falls outside a limit. The required specifications depend on the component and finished product; this workflow does not establish universal magnesium glycinate limits. [2]
Sources & further reading
- FDA: Dietary supplement CGMP small entity compliance guide
- 21 CFR 111.70: Component, process and finished-product specifications