How to read cannabis lab reports (Certificate of Analysis).

Every legal cannabis product sold in Arizona is required to have a Certificate of Analysis (COA) from a state-licensed testing laboratory. The COA tells you exactly what's in the product — cannabinoid content, terpene profile, and whether it's free of contaminants. Knowing how to read one helps you pick better products, dose more accurately, and avoid contaminated batches.

How to find a product's COA

In Arizona, you can usually find the COA by:

• Asking the budtender — they should be able to scan a QR code or pull up the lab report
• Checking the dispensary's website — most post COAs on each product page
• Searching the AZDHS product database by batch/lot number

If a dispensary can't show you a COA, that's a red flag.

Section 1: Cannabinoid profile

The first section of most COAs lists the cannabinoid content. You'll typically see:

THC and THCA

For flower, you'll see both THCA and THC listed separately. Raw cannabis contains mostly THCA, which converts to THC when heated (decarboxylation). The COA usually shows total THC (THCA × 0.877 + THC), which represents the active THC you'll feel when smoking or vaporizing.

CBD and CBDA

Same pattern as THC. Most flower has low CBD (<1%). Hemp flower and CBD-dominant strains show high CBDA and CBD.

Minor cannabinoids

Higher-end COAs also report:

• CBG — anti-inflammatory, antibacterial
• CBN — sedative, useful for sleep
• THCV — appetite suppressant, energetic
• CBC — anti-inflammatory, mood

The "minor" cannabinoids often contribute significantly to the effect, especially when present in meaningful amounts (>0.5%). The "entourage effect" — the idea that cannabinoids work better together — is supported by emerging research.

Total cannabinoid content

For edibles, COAs list total mg of each cannabinoid per package and per serving. For example, a 100mg THC edible in 10 servings = 10mg THC per serving. Always verify this matches the label.

Section 2: Terpene profile

The terpene section is where the really interesting therapeutic info lives. You'll see percentages of the dominant terpenes — usually the top 5–10.

The most common cannabis terpenes and what they do:

Terpene	Aroma	Effects
Myrcene	Earthy, musky	Sedating, anti-inflammatory, muscle-relaxing
Limonene	Citrus	Mood-elevating, anti-anxiety, energizing
Caryophyllene	Pepper, spice	Anti-inflammatory (unique — also binds CB2), analgesic
Pinene	Pine	Alertness, anti-inflammatory, bronchodilator
Linalool	Floral, lavender	Calming, anti-anxiety, sedating
Humulene	Hops, woody	Anti-inflammatory, appetite suppressant
Terpinolene	Floral, herbal	Mildly sedating, antioxidant
Ocimene	Sweet, herbal	Energizing, anti-inflammatory

Total terpene content is usually 1–3% in flower. Higher terpene percentages (>2%) often correlate with better smell, flavor, and effect — this is sometimes called "loud" or "dank" cannabis.

Section 3: Contaminant testing

This is the most important section for safety. Arizona requires testing for:

Pesticides

A list of approved limits for various pesticides. Common findings:

• "PASS" or "ND" (not detected): safe
• "<LOQ" (less than limit of quantification): trace amounts, technically within limits but worth noting
• "FAIL": avoid this product; report to dispensary

Particularly concerning pesticides include myclobutanil (often used for powdery mildew) and bifenthrin — both can become dangerous when combusted.

Heavy metals

Lead, arsenic, cadmium, and mercury are tested. Cannabis plants are hyperaccumulators and pull heavy metals from soil. Arizona requires testing for the four primary heavy metals, with limits varying by product type.

Microbial contaminants

Tests for:

• Total aerobic bacteria
• Total yeast and mold
• E. coli and Salmonella
• Aspergillus (especially dangerous for immunocompromised patients)

For medical patients with compromised immune systems, microbial testing is critical. Look for "PASS" on all microbial panels.

Residual solvents

For concentrates and extracts, this tests for leftover solvents from the extraction process (butane, propane, ethanol, CO2). Solvent-free or "rosin" products skip this entirely. Properly purged extracts show "PASS" or "ND."

Mycotoxins

Toxins produced by certain molds. Especially important for immunocompromised medical patients.

Foreign matter

Tests for things like hair, insects, or other contaminants that shouldn't be in the product.

Red flags to watch for

• No COA available — never buy from a source that can't provide one
• Old COA — labs and batches should match the actual product you're buying
• Lab is not accredited — Arizona requires ISO 17025 accredited labs, but verify the lab name
• Cannabinoid percentages suspiciously high — if a "30% THC" claim has no COA backing it up, walk away
• Failed contaminant panels — obvious no-go
• No terpene data — the lab didn't run the test, or the dispensary isn't sharing it. Common for low-quality product

How to use the COA to choose better products

For sleep

Look for products high in myrcene (>0.4%), linalool (>0.2%), and CBN. THC content of 15–25% is usually sufficient.

For daytime anxiety

Look for products high in limonene, pinene, and linalool. Lower THC (<15%) and higher CBD (5–10mg per dose) for daytime.

For chronic pain

Look for products high in caryophyllene (the most analgesic terpene) and beta-myrcene. Balanced THC:CBD ratios.

For focus and energy

Look for products high in pinene, limonene, and terpinolene. Lower doses of THC. Avoid myrcene-dominant strains.

COA vs. label

Always verify the COA against the product label. Common discrepancies:

• Label claims 100mg THC per package; COA shows 87mg — significant discrepancy, return the product
• Label says "25% THC"; COA shows 18% — slight discrepancy, acceptable but worth noting

Small variations (within 5–10%) are normal. Larger discrepancies suggest the COA may not match the actual product batch.

How often COAs are updated

A COA is generated for each production batch. The same product strain from the same grower may have slightly different cannabinoid content from batch to batch. Most dispensaries update COAs within 1–2 weeks of receiving new inventory. If a COA is more than 6 months old, ask if it's current.

The bottom line

COAs are a powerful tool. Spend 5 minutes learning the format, and you'll never buy a contaminated or mislabeled product again. Ask your budtender for COAs — any reputable dispensary will have them readily available. If they can't, consider that a sign of poor quality control and shop elsewhere.

For medical patients, especially immunocompromised ones, the contaminant panels are essential — not optional — to review.