How to Read a Cannabis Lab Test Report (COA) Like a Pro

A Certificate of Analysis (COA) is an independent laboratory’s report on what is actually in a cannabis product. Reading one well turns marketing claims into verifiable data. This guide focuses on the sections that matter most to a consumer.

Potency section

Look for total THC, total CBD, and any other listed cannabinoids. “Total” usually accounts for the acidic forms (THCA, CBDA) that convert when heated. Compare the numbers to the package label. Large discrepancies are a red flag.

Terpene profile

When present, this list shows the dominant aromatic compounds and their percentages. It is one of the best predictors of the sensory experience. High total terpene content often correlates with stronger aroma and more complex effects.

Residual solvents

Relevant for extracts made with hydrocarbons or ethanol. Results should fall below action limits (or show “not detected”). Solventless products should ideally show no residual solvents of concern.

Contaminant panels

• Pesticides — should be non-detect or below strict limits
• Heavy metals — especially important for products that will be inhaled or used frequently
• Microbials — yeast, mould, bacteria; presence above limits is unacceptable
• Mycotoxins — sometimes tested alongside microbials

Sample information and dates

Check that the sample ID and batch number match the product you hold. Note the test date — very old reports may not reflect the current batch. Reputable producers test every batch or every production run.

Pass / fail summaries

Many COAs include a clear pass/fail for each category. A single failure in contaminants is usually reason to avoid the product.

Practical habit

Ask for the COA. Reputable retailers and producers make them easy to access. Spending thirty seconds scanning potency, terpenes and the contaminant summary gives you more real information than any product description.