What Is a Certificate of Analysis (COA)?

A certificate of analysis is a lab report proving what's actually in your product — not what the label claims, what an independent lab measured. If you sell hemp, CBD, or any consumable product, customers and regulators both expect one to exist.

What it actually is

A COA is issued by a third-party testing lab — not you, not your manufacturer — after they run a physical sample of a specific production batch through their equipment. It reports back hard numbers: what compounds are present, how much, and whether anything unwanted (contaminants, pesticides, heavy metals) showed up.

The key word is independent. A COA only means something if the lab has no stake in the result. That's why reputable labs carry accreditation — most commonly ISO/IEC 17025, the standard for testing lab competence.

What's actually on one

A real COA typically includes:

• Batch or lot number — ties the results to one specific production run, not "the product in general"
• Test date — how recent the results are
• Cannabinoid profile — the percentage of each compound tested (THC, CBD, and others, depending on the product)
• Contaminant screening — pesticides, heavy metals, residual solvents, microbials — whatever's relevant to the product type
• The lab's name, accreditation, and signature — so the result is traceable and accountable

Why customers actually check

Hemp and CBD buyers have been burned by mislabeled products before — bottles claiming 1000mg that test at a fraction of that, or worse, contamination that never should have shipped. A visible, per-batch COA is how a buyer tells a serious brand from one cutting corners. It's also, increasingly, the law: several states now require a QR code or URL on the label linking straight to it — see our state-by-state rundown.