CANNABIS EXPLAINER
Certificate of Analysis (COA)
The COA is your proof that cannabis has been tested and is safe.
CANNABIS EXPLAINER
The COA is your proof that cannabis has been tested and is safe.
A Certificate of Analysis (COA) is a document issued by an accredited cannabis testing laboratory that summarizes the results of testing performed on a specific cannabis sample. In legal cannabis markets, a COA is required before products can be sold at dispensaries. The COA confirms that the product meets regulatory standards for potency and safety.
A standard cannabis COA contains: the laboratory name, address, and license number; sample identification number and date collected; product description and batch number; cannabinoid potency results (mg/g or percentage); terpene profile (optional but common); contaminant test results including pesticides, heavy metals, microbiological agents, and residual solvents; and pass/fail determinations for each category.
Most legal cannabis products include a QR code on the packaging that links directly to the COA on the testing lab's website. Scan the QR code and verify that the batch number on the label matches the sample ID on the COA. Check the lab's accreditation credentials — reputable labs are ISO/IEC 17025 certified. Be suspicious of COAs without dates, without lab contact information, or with unusually high potency results.
COA potency sections list each cannabinoid detected. The most important are THC and THCA for psychoactive products, and CBD and CBDA for hemp products. Results are typically shown as percentage by weight and as mg per gram. Some COAs show "Total THC" which is the calculated potency accounting for THCA decarboxylation: Total THC = (THCA × 0.877) + THC.
Pass/fail results for contaminants are equally important as potency. Check that all categories show "PASS" or "ND" (not detected). If any pesticide, heavy metal, or microbial contaminant shows a value above the regulatory limit, the product should not be sold. If you purchase a product and later find a failed COA, contact the dispensary and your state's cannabis regulatory agency.