Quality
How to read a supplement COA
Certificates of analysis can look dense. Here’s what to check before you trust a brand’s purity claims.
A certificate of analysis (COA) is a lab report for a specific batch. Brands that publish COAs make it easier to verify what is — and is not — in the bottle. A glossy “lab tested” badge without a report is not the same thing.
Start with identity and potency: does the report confirm the labeled active, and does the measured amount match the Supplement Facts claim within a reasonable tolerance? Then scan contaminant panels for heavy metals, microbes, and solvents when relevant to the ingredient.
Match the lot or batch number on your bottle to the COA. A report from a different SKU or an outdated lot does not validate the product in your hand. Prefer ISO-accredited or similarly reputable labs, and be wary of reports that omit methods or detection limits.
If a brand cannot produce a recent, batch-matched COA on request, treat purity claims as marketing until proven otherwise.