How to Read a Certificate of Analysis (COA)
By Vault Extracts, Biochemistry Engineer · Published July 17, 2026
A Certificate of Analysis (COA) is a third-party lab report that tells you what's actually in a product. Knowing how to read one is the single best habit for buying hemp online. Here's what each part means.
What a COA is (and why it matters)
A COA is issued by an independent, accredited lab — not the seller. It verifies a product’s cannabinoid content and screens for contaminants. Reputable sellers make a COA available for every batch. If a product has no COA, that’s a reason to walk away.
The potency / cannabinoid panel
This is the section most people check first. It lists each cannabinoid by weight or percentage — THCA, Delta-9 THC, CBD, and others. For hemp flower you’ll typically see a high THCA number and a low Delta-9 THC number. Totals are sometimes shown as “Total THC,” which factors in how much THCA converts to THC when heated.
The safety panels
Beyond potency, a thorough COA screens for things you don’t want to inhale or ingest:
- Pesticides — should read “pass” or below limits.
- Heavy metals — lead, arsenic, cadmium, mercury.
- Microbials — mold, yeast, harmful bacteria.
- Residual solvents — relevant for extracts and carts.
A clean report shows “pass” across these panels.
How to confirm a COA is real
- Check the lab’s name and contact — you should be able to look them up.
- Match the batch or sample ID on the COA to the product.
- Note the date — results should be recent enough to be relevant.
- Watch for a QR code or verification link that opens the report directly from the lab.
Frequently asked questions
What does 'Total THC' mean on a COA?
Total THC estimates how much THC a product delivers after heating, combining existing Delta-9 THC with the portion of THCA that converts when decarboxylated.
Should every product have a COA?
Yes. A reputable seller provides a batch-specific COA from an independent lab. No COA is a red flag.
What if a COA has no safety panels?
Potency alone isn't enough. Look for pass results on pesticides, heavy metals, microbials, and (for extracts) residual solvents.
For adults 21+. THCA products are lab-tested with a Certificate of Analysis available. Cannabinoid laws vary by state and change often — check the current rules where you live. Nothing here is medical or legal advice.