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THCA vs. delta-9 THC: what the label means
Two names, two compounds
THCA is short for tetrahydrocannabinolic acid. It's the form THC takes in the living plant and in raw, unheated flower. Delta-9 THC (often written Δ9-THC) is the compound most people mean when they say "THC." Chemically, the two differ by one small group of atoms, a carboxyl group, that THCA carries and delta-9 THC doesn't.
Because they're different compounds, a lab measures them separately, and a label or lab report lists them on separate lines. That's why a single jar of flower can show one number for THCA and a much smaller number for delta-9 THC.
What heat does
When THCA is heated, for example when flower is smoked or vaped, that carboxyl group breaks off as carbon dioxide. Chemists call this decarboxylation. What's left is delta-9 THC. This is the key fact behind every THCA label: the THCA number describes the product as it sits in the jar, not what it becomes once it's heated.
Where you'll see each number
- Flower, pre-rolls and concentrates usually list THCA and delta-9 THC as percentages of weight. You'll find these in our THCA flower and THCA concentrates categories.
- Vapes list cannabinoids as a percentage or in milligrams per device. See our vapes.
- Edibles and drinks list delta-9 THC in milligrams (mg) per serving and per package, because you eat or drink a set amount. Examples on our shelves include LIVE Fruit Chews and Finer Daze Lavender Lemonade.
A percentage tells you how much of the product's weight is that compound. Milligrams tell you a fixed amount. The two aren't interchangeable, so compare like with like.
How "total THC" is calculated
Most lab reports include a line called total THC. It estimates how much delta-9 THC the product would contain if all of its THCA were converted. The common formula is:
Total THC = delta-9 THC + (0.877 × THCA)
Why 0.877? When THCA loses its carboxyl group, it loses some weight. A THCA molecule weighs about 358 units and a delta-9 THC molecule about 314, and 314 ÷ 358 is roughly 0.877. So each unit of THCA can become, at most, about 0.877 units of delta-9 THC.
A worked example (made-up numbers, not a product we sell): say a lab report shows 20% THCA and 0.2% delta-9 THC. Multiply 20 by 0.877 to get 17.54, then add 0.2. Total THC is 17.74%. That's the number to look at if you want to know the combined THC content after heating.
For real products, never rely on our math or anyone's marketing. Use the numbers on the batch lab report for the exact product in your hand.
Reading the lab report
A lab report, also called a certificate of analysis or COA, is a document from a testing lab. On the cannabinoid page you'll usually see a table with these columns:
- Analyte: the compound tested, such as THCA, Δ9-THC, CBD or CBG.
- Result: the amount found, as a percentage, mg/g or mg per unit.
- LOQ or LOD: the smallest amount the lab can reliably measure or detect.
- ND: "not detected," meaning the amount was below what the lab can detect.
Below the table there's often a "total THC" line using the formula above. Check that the batch number on the report matches the batch number on your package, and look at the test date. Batch lab reports for each category are on our Lab reports page, and you can scan the QR code on the shelf tag in the store.
THCP is a different compound
You'll also see THCP on some labels, including in our THCP category. THCP is a separate, less common cannabinoid. It isn't the same as THCA or delta-9 THC and isn't part of the total THC formula above. Read its own line on the label and the lab report.
Questions to ask before you buy
- Does the label list THCA, delta-9 THC and total THC, or only one of them?
- Is the number a percentage or milligrams, and per what (gram, serving, package)?
- Does the batch number on the package match a lab report you can read?
- When was the batch tested, and is there an expiration date?
If any of that is unclear, ask anyone on our team at 1107 West North Boulevard in Leesburg, or call (352) 805-7659. We'll pull up the lab report with you.
THCA and delta-9 questions
Is THCA the same as delta-9 THC?
No. THCA is the acid form found in the raw plant. Heating it, for example by smoking or vaping, converts it to delta-9 THC, which is intoxicating and can cause a positive drug test. Don't drive or operate machinery after use.
What does total THC mean on a lab report?
It's an estimate of the delta-9 THC a product would contain if all of its THCA were converted. The common formula is delta-9 THC plus 0.877 times THCA.
Why is the factor 0.877?
THCA loses a carboxyl group as carbon dioxide when heated. Delta-9 THC weighs about 0.877 times as much as THCA, so that's the most delta-9 THC each unit of THCA can become.
Where can I see the lab report for a product?
Batch lab reports for each category are on our Lab reports page, and you can scan the QR code on the shelf tag in the store. Check that the batch number matches your package.