The Certificate of Analysis is the single most information-dense document in ingredient sourcing. Here is how experienced QA teams read one.
Assay — the number that defines price
The assay line states the marker compound content and the method (UV, HPLC). Two rules: the method must be named, and the result must sit comfortably inside the specification, not exactly on the limit.
Appearance and organoleptic
Color and particle description should match the sample on your bench. A mismatch between COA and material is the cheapest red flag you will ever catch.
Loss on drying
High moisture shortens shelf life and can mask assay dilution. Food-grade botanical powders typically specify ≤ 5%.
Heavy metals
Look for individual limits on lead, arsenic and mercury rather than a single lumped value. Limits should reference the pharmacopoeia or regulation of your destination market.
Microbiology
Total plate count, yeast and mold, E. coli and Salmonella. For ingredients going into finished supplements, confirm the limits align with your finished-product spec.
The meta-check
A lot-specific COA has a lot number that matches the drums, a manufacture date, and a signature. Generic 'representative' COAs are fine for evaluation — but every shipment must carry its own.
Every BolinHerb lot ships with a lot-specific COA. Request a representative copy for any product through the AI assistant or contact page.