How to Read a Cannabis Certificate of Analysis (COA)

If you've ever purchased a cannabis product from a licensed dispensary, you may have noticed a QR code or laboratory report called a Certificate of Analysis, commonly known as a COA.

A COA is one of the most important consumer protection tools in the legal cannabis industry. It provides independent laboratory verification of what is in a product—and just as importantly, what is not.

To better understand how a COA works, let's examine a real-world example: a California compliance report for Dr. Norm's Mini Sleep Brownies.

What Is a COA?

A Certificate of Analysis is a laboratory report generated by a licensed, independent testing laboratory.

Before legal cannabis products can be sold in California, they must undergo a series of tests designed to verify potency and screen for contaminants.

The resulting COA serves as a record of those findings.

Think of it as a report card for the product.

Step 1: Verify the Product Information

The first section of a COA identifies the product being tested.

In this example, the report shows:

• Product: Dr. Norm's Mini Sleep Brownies
• Product Type: Baked Goods
• Matrix: Ingestible
• Batch Number: SLP-BROWNIES-003
• Producer: Punch Media, LLC
• Testing Laboratory: Landau Laboratories, Inc.

Consumers should always verify that the product in their hand matches the information on the laboratory report.

Step 2: Review the Summary Results

One of the most important sections appears on the first page.

This summary provides a quick overview of every major compliance category tested.

In this example, the product received passing results for:

✓ Cannabinoids

✓ Pesticides

✓ Heavy Metals

✓ Residual Solvents

✓ Microbials

✓ Mycotoxins

✓ Water Activity

✓ Foreign Matter

When reviewing a COA, consumers should look for "Pass" results across all required categories.

Step 3: Understand Potency

The cannabinoid section tells consumers exactly what cannabinoids were found and in what amounts.

For this batch:

• THC: 9.952 mg per serving
• CBN: 5.064 mg per serving
• Total Cannabinoids: 15.016 mg per serving

This information allows consumers to make informed decisions regarding serving size and product selection.

Without laboratory testing, potency claims may be impossible to verify.

Step 4: Look at Pesticide Testing

Cannabis plants can be exposed to pesticides during cultivation.

California requires licensed products to be screened against a long list of pesticide compounds.

In this report, every pesticide tested was reported as:

ND (Not Detected)

or

Pass.

This provides reassurance that the product met California's regulatory standards for pesticide screening.

Step 5: Review Heavy Metal Screening

Cannabis can absorb substances from soil and water.

For this reason, laboratories screen for contaminants such as:

• Lead
• Mercury
• Arsenic
• Cadmium

In this example:

• Arsenic: Not Detected
• Lead: Not Detected
• Mercury: Below reporting limits
• Cadmium: Passed regulatory requirements

Heavy metal testing is one of the most important consumer protections within regulated cannabis markets.

Step 6: Check for Microbial Contamination

Microbial testing screens for harmful organisms that could present health concerns.

This batch tested:

• Negative for Salmonella
• Negative for Shiga toxin-producing E. coli

These results help verify that the product meets safety standards before reaching consumers.

Step 7: Understand Residual Solvent Testing

Some cannabis products are produced using extraction processes.

Residual solvent testing verifies that any solvents used during manufacturing remain below regulatory limits.

This batch passed all required residual solvent testing.

Why COAs Matter

One of the biggest differences between licensed cannabis products and unregulated products is transparency.

Licensed products undergo testing.

Unlicensed products often do not.

Consumers purchasing products from unlicensed retailers, informal delivery services, social media sellers, or so-called "trap shops" may have no independent verification regarding potency, contaminants, manufacturing practices, or ingredient sourcing.

The same concerns can apply to some intoxicating hemp-derived products sold outside regulated cannabis channels. Depending on the jurisdiction and product category, testing and oversight standards may differ significantly from those applied to licensed cannabis products.

A COA helps eliminate much of that uncertainty by providing independent laboratory verification.

The Bottom Line

A Certificate of Analysis is one of the most valuable tools available to cannabis consumers.

It verifies potency.

It screens for contaminants.

It promotes transparency.

Most importantly, it helps consumers understand exactly what they are purchasing.

When evaluating cannabis products, one simple question can go a long way:

"Can I see the COA?"

If the answer is yes, consumers can review objective laboratory data. If the answer is no, it may be worth asking why.