Quality & Lab Testing
How to Read a CBD Certificate of Analysis (COA): A Buyer’s Checklist
Potency, THC details, contaminant panels, and the red flags that signal low quality.
Key takeaways
- A COA is a third‑party lab report that confirms potency and screens for contaminants.
- Always match the COA to your batch/lot number.
- Look beyond cannabinoids: aim for heavy metals, pesticides, solvents, microbes.
- Use COAs to verify “THC‑free” claims.
Table of contents
What is a COA?
A Certificate of Analysis (COA) is a lab report that helps confirm what’s in a CBD product (potency) and what’s not (contaminants).
New to CBD? Start here: CBD 101.
Step 1: Match the COA to your exact batch
- Product name matches what you bought
- Lot/batch number matches the label
- Test date is reasonable/recent
- Lab name and contact details are visible
Step 2: Read the cannabinoid potency panel
You may see results as % by weight, mg/g, or mg/mL (tinctures). A good sanity check is whether the label claim roughly matches the COA once you account for serving size.
Step 3: Check THC details
Even if you don’t “care” about THC, THC reporting can matter for intoxication risk and workplace policies.
Step 4: Look for contaminant testing
- Heavy metals (lead, arsenic, cadmium, mercury)
- Pesticides
- Residual solvents (especially for extracts)
- Microbials (mold/yeast/bacteria)
Full quality overview: Third‑Party Lab Testing for Hemp Products.
COA red flags (avoid these)
- No batch number or it doesn’t match your product
- Only potency listed; no contaminant panels
- COA is very old with no explanation
- Lab identity unclear/unverifiable
- Numbers don’t align with label claims