How to Actually Read a Certificate of Analysis Before Buying a Supplement

At minimum, a legitimate COA should show three things: the specific batch number matching the product you're holding (not a generic or outdated COA reused across batches), the testing lab's name and accreditation (in India, look for NABL accreditation specifically), and the actual tested values for potency and contaminants, not just a pass/fail summary. If a brand only provides a certificate stating 'this product passed testing' without the underlying numeric data, that's a meaningfully weaker document than a full quantitative COA.

For herbal extracts specifically, check that the COA verifies the active compound standardization claimed on the label — for example, if a product claims '5% withanolides' for an ashwagandha extract, the COA should show a lab-measured withanolide percentage, not just a general purity pass. A product can be technically free of contaminants while still containing a much lower concentration of the active compound than advertised, and only a compound-specific test catches that gap.

Heavy metal testing matters particularly for Ayurvedic formulations sourced from soil-grown herbs, since lead, arsenic, mercury, and cadmium can accumulate in certain plants depending on growing conditions. A trustworthy COA reports specific parts-per-million values for each of these four metals against recognized safety thresholds, rather than a vague 'heavy metals: within limits' statement.

Finally, batch specificity is the detail most easily faked or omitted. A rotating batch number that changes with each new COA posted suggests ongoing testing discipline; a single static COA that never changes, sometimes with an old date, is a signal the brand tested once early on and hasn't repeated the process since. When in doubt, it's reasonable to email the brand directly and ask for the COA matching the specific batch number printed on your product's packaging.