A Certificate of Analysis (COA) is a third-party lab report showing what's actually in a CBD product. You need to check three things: CBD potency (does it match the label?), THC content (below 0.3% for legal hemp — or 0% for isolate), and contaminants (pesticides, heavy metals, solvents, microbes). If a brand can't show you one, that's your answer.
The sections that matter
| Section | What it tells you | What to look for |
|---|---|---|
| Potency / cannabinoid profile | How much CBD (and other cannabinoids) | CBD mg/g should roughly match the label claim |
| THC content | Delta-9 THC level | Below 0.3% (hemp); 0% for isolate products |
| Pesticides | Residual pesticide residue | ND (not detected) or under state limits |
| Heavy metals | Lead, arsenic, cadmium, mercury | ND or under action limits |
| Solvents | Residual extraction solvents | ND or under limits (CO2 extraction leaves almost none) |
| Microbials | Mold, yeast, bacteria | ND or under limits |
How to verify a COA is real
- Find the lab's name and the batch/COA number. A real report always has both.
- Go to the lab's website. Most reputable labs publish a searchable report database. Enter the COA number.
- Check the date. The test should be recent — ideally the same batch you're buying, not last year's.
- Beware the screenshot. A COA that can't be found on the lab's own site may be edited, borrowed, or fake. Verification takes two minutes.
Red flags that mean "move on"
- No COA at all — the brand can't or won't prove what's in the bottle.
- Potency that doesn't match the label — a 1,000 mg label with a 600 mg test result means you're overpaying.
- THC above 0.3% — federally "hot" hemp, a genuine legal and drug-test risk.
- A lab you've never heard of — check that it's actually accredited/ISO-certified.
Why this matters at Simple Tinctures
Our whole pitch is that CBD is a commodity and you shouldn't pay 20× for branding. That only works if the product is exactly what we say it is — pure isolate, 0% THC, at the labeled potency. That's why we publish our lab results openly, and why we keep the price at ~$0.006/mg (see the cost comparison). If you're comparing brands, use the COA, not the story. Here's also how to choose what to buy once the report checks out.