How to Read a Cannabis Lab Report (COA) Before You Buy

Learning how to read a cannabis lab report (COA) is the single most useful skill a THCA shopper can pick up. A Certificate of Analysis tells you how potent a product really is, what terpenes drive its flavor and effect, and whether it was screened for pesticides, heavy metals, mold and solvents. This guide walks you through every panel on a typical COA, shows you the THCA to total THC math, and flags the warning signs that should make you close the tab and shop elsewhere.

What a Cannabis COA Actually Is

A COA, or Certificate of Analysis, is a document produced by a laboratory after testing a specific batch of cannabis or hemp. For hemp-derived THCA products, it is also the paperwork that shows the flower stays under the federal 0.3% delta-9 THC limit by dry weight. If you want the legal background first, our explainer on whether THCA is legal under the Farm Bill covers it in plain English.

Most COAs run two to six pages. Page one is a summary with the big numbers; the pages behind it hold the detailed panels and the lab's methods and accreditation.

How to Read a Cannabis Lab Report: Start With the Header

Before you look at a single percentage, check the header. It should list the lab's name and address, the client (the brand or grower), the product name, the sample type (flower, concentrate, edible), and a batch or lot number. It should also show the date the sample was received and the date the report was issued.

Look for an accreditation mark, usually ISO/IEC 17025, and a signature from the lab director. Then match the batch number on the COA to the batch number on the packaging or product page. If they do not match, the report describes a different harvest, not the one you are about to buy.

The Potency Panel: Cannabinoids Explained

The cannabinoid or potency panel is what most shoppers care about. It lists each cannabinoid the lab tested for, with results typically shown as a percentage by weight and as milligrams per gram. Common rows include THCA, delta-9 THC, CBDA, CBD, CBGA, CBG, CBN and sometimes minor cannabinoids like THCV or CBC.

For THCA flower, you will usually see a high THCA number and a low delta-9 THC number. That pattern is the whole point. THCA is the non-intoxicating acid form that lives in raw flower, and it converts to delta-9 THC when heated. Our guide to THCA vs THC explains that relationship in depth.

You will also see two abbreviations on nearly every panel. ND means "not detected" at the lab's detection limit. LOQ means "limit of quantitation," the smallest amount the lab can measure with confidence. A value marked "<LOQ" was detected in a trace amount but is too small to assign a reliable number.

THCA vs Total THC: The 0.877 Math

This is the part that confuses almost everyone. When THCA is heated, it loses a carboxyl group and becomes THC. That lost group has mass, so one gram of THCA does not become one gram of THC. The conversion factor is 0.877, which reflects the molecular weight difference between the two compounds.

The standard formula labs use is:

Total THC = (THCA x 0.877) + delta-9 THC

Here is a worked example using numbers that are typical for premium THCA flower:

Line Item	Result	What It Means
THCA	25.0%	Acid form present in raw flower
Delta-9 THC	0.15%	Active THC already present (must be under 0.3%)
THCA x 0.877	21.9%	THC you would get after full conversion
Total THC	22.1%	21.9% + 0.15%, the potency after heating

So a flower that reads 25% THCA has a total THC of roughly 22%, not 25%. Some brands advertise the raw THCA number and others advertise total THC. Neither is wrong, but know which one you are looking at before you compare two products. This is also why a COA can show total THC above 20% while still being compliant hemp: the compliance test looks at delta-9 THC by itself.

The Terpene Panel

Not every COA includes terpenes, but the good ones do. The terpene panel lists aromatic compounds like myrcene, limonene, beta-caryophyllene, linalool, pinene and terpinolene, each as a percentage by weight, with a total at the bottom.

Total terpene content in dried flower is often reported in the 1% to 3% range, and anything above roughly 2% is commonly described as loud or terpene-rich. The dominant terpene tells you a lot about aroma: myrcene often smells earthy, limonene leans citrus, and caryophyllene brings pepper and spice.

A terpene panel is also a quick authenticity check. If a strain is sold as citrus-forward but the panel shows almost no limonene, the label and the lab disagree. For a deeper dive, see our cannabis terpenes guide.

Contaminant Panels: Pesticides, Heavy Metals, Microbials and Solvents

Potency is the fun part of a cannabis lab report, but the safety panels are the reason COAs exist. A full-panel COA includes four contaminant screens, each listing the analyte, the action limit, the result and a Pass or Fail.

Pesticides

Labs screen for dozens of pesticides, fungicides and plant growth regulators, with names like myclobutanil and paclobutrazol. You want to see ND or Pass on every line. Flower is smoked or vaporized, so residue matters more here than it does on a salad.

Heavy Metals

Cannabis is a bioaccumulator, meaning the plant pulls metals out of soil and water. The standard panel covers arsenic, cadmium, lead and mercury. Results are shown in parts per million (ppm) or micrograms per gram, compared against an action limit. Again, ND across the board is the goal.

Microbials

This panel screens for mold, yeast, E. coli, Salmonella and sometimes Aspergillus species. Results may appear as colony-forming units per gram (CFU/g) or as Present/Absent. Flower that was dried or stored poorly tends to fail here first. Proper storage keeps a clean batch clean.

Residual Solvents

This panel matters most for concentrates. Badder, diamonds and sugar diamonds are often made with hydrocarbon solvents like butane or propane, and the finished product should have those purged down to trace levels or ND. Flower and solventless products may show this panel as "not applicable." If you shop concentrates, our breakdown of badder, diamonds and sugar explains why solvent testing is non-negotiable.

Some COAs also include mycotoxins, moisture content and water activity. Moisture is typically reported in the 8% to 12% range for well-cured flower.

Red Flags on a Cannabis Lab Report

Once you know the layout, spotting a weak COA takes about thirty seconds. Watch for these warning signs:

• Potency-only testing. A report that shows cannabinoids and nothing else tells you the flower is strong, not that it is clean.
• No batch number, or a batch that does not match the product. The report may be legitimate but it does not describe what you are buying.
• Old dates. A COA from two or three years ago on a product sold as fresh is a mismatch worth questioning.
• Suspiciously round or extreme numbers. THCA results well above 30% on flower are rare and deserve a second look at the lab's credentials.
• Delta-9 THC above 0.3%. For a hemp-derived product, this fails the federal definition no matter what the rest of the page says.
• No lab accreditation or contact details. Reputable labs put their ISO accreditation number and address on every page.
• Brand-run "in-house" testing presented as independent. Internal QC is fine as a supplement, but it does not replace third-party results.

Why Third-Party Testing Matters

A brand that tests its own product has an obvious incentive to report what sells. An independent, accredited lab has the opposite incentive: its reputation depends on being right, and a lab caught inflating numbers loses its accreditation and its clients. That is why third-party COAs carry weight and in-house results do not.

Third-party testing also catches problems the grower might not know about, like heavy metals from contaminated soil or microbial growth from a humid cure room. The grower sees beautiful flower. The lab sees what is in it.

At Elevana we publish batch-specific, full-panel COAs from accredited third-party labs for every strain we sell, and we encourage you to read them before you add anything to your cart. You must be 21 or older to purchase, and you should always check your local laws, since state rules on hemp-derived THCA vary and change. If you want to know what else separates premium flower from the rest, our article on what makes top-shelf flower picks up where the lab report leaves off.

Frequently Asked Questions

How do I read a cannabis lab report if I only have a minute?

Check three things: the batch number matches your product, delta-9 THC is under 0.3%, and every contaminant panel says Pass. Then glance at the THCA percentage and the total terpene number. That quick pass covers compliance, safety and quality in under sixty seconds.

Why is total THC lower than the THCA percentage on my COA?

Because THCA loses mass when it converts to THC through heat. Labs multiply THCA by 0.877 and add any delta-9 THC already present to estimate total THC. A 25% THCA flower therefore has a total THC of roughly 22%.

What does ND mean on a cannabis COA?

ND stands for "not detected." It means the lab's equipment found none of that compound above its detection threshold. On a contaminant panel, ND is exactly what you want to see. On a cannabinoid panel, ND next to delta-9 THC simply means the flower is almost entirely THCA.

Is a COA without a terpene panel a red flag?

Not necessarily. Terpene testing costs extra and some growers skip it, especially on smaller batches. It is a missed opportunity rather than a safety concern. A missing contaminant panel, on the other hand, is a real red flag.

How can I verify that a COA is real?

Look for a QR code or report ID and check it on the lab's own website rather than the brand's. Confirm the lab is accredited and that the client name on the report matches the brand selling the product. If a report cannot be verified independently, treat it as unverified.

Do THC gummies and pre-rolls get the same kind of COA?

Mostly, yes, but the units change. Edibles report cannabinoids in milligrams per serving and per package rather than percentages. Infused pre-rolls may list the flower and the concentrate separately.

Shop Flower You Can Verify

Now that you know how to read a cannabis lab report, put it to use. Every strain in the Elevana collection ships with a batch-matched, full-panel COA you can read before you buy, so you can compare THCA, total THC and terpene content with confidence and skip the guesswork.

This article is for informational purposes only and is not medical or legal advice. Hemp-derived THCA products contain less than 0.3% delta-9 THC by dry weight. THCA converts to THC when heated. Keep all products away from children and pets. Do not drive or operate machinery after use.