How to Read a COA: Total THC, THCA and the Dec. 11 Hemp Rules

Mainstream CBD | Lakeville, MN

Every hemp product we sell comes with a Certificate of Analysis, or COA. It's the lab report that shows what's actually in the package. Most people never open one, and honestly, we get it. A COA can look like a page of chemistry homework. But reading one is easier than it looks, and it's about to matter more than ever.

Federal hemp rules are changing. Starting December 11, 2026, the federal definition of hemp moves from a delta-9-only test to a total THC standard that counts THCA, and it adds a cap of 0.4 milligrams of total THC per container for finished products. Knowing how to read a COA helps you understand what you're buying today and why the rules are such a big deal for products like THCA flower, gummies and drinks.

Here's a plain-English walkthrough from our Lakeville counter.

Quick legal update: what's changing and when

Late last year Congress included a hemp redefinition in Public Law 119-37. It was set to take effect November 12, 2026. In September, the stopgap funding bill (H.R. 6500) delayed most of it to December 11, 2026. Here's where things stand as of this week:

• November 12, 2026: Products containing cannabinoids that a cannabis plant can't naturally produce lose federal hemp status.
• December 11, 2026: The rest of the redefinition kicks in. That includes the total THC test (THCA counts), the 0.4 mg total THC per container cap, and the exclusion for naturally occurring cannabinoids manufactured outside the plant.
• Until then: The current 0.3% delta-9 THC standard still applies.

December 11 is also the date government funding runs out, so Congress could change the hemp rules again before then. We're watching closely and will post updates on this blog. For the bigger picture, see our Federal Hemp Ban 2026 Update.

What is a COA?

A Certificate of Analysis is a report from a laboratory that tested a specific batch of product. A good COA tells you:

• Who tested it: the lab's name, contact info and, ideally, its accreditation (look for ISO/IEC 17025).
• What was tested: product name, batch or lot number, and sample type (flower, gummy, vape oil, etc.).
• When: the date the sample was received and the date results were reported.
• What's in it: the cannabinoid profile, and often safety screens for contaminants.

Tip: The batch number on the COA should match the batch number on your package. If it doesn't, it's not your product's report.

Step 1: Find the cannabinoid profile

This is the table most people care about. It lists cannabinoids like CBD, CBDA, CBG, CBN, delta-9 THC, THCA and sometimes delta-8. Each one usually has a few columns:

• % (percent by weight): common for flower and concentrates.
• mg/g: milligrams per gram. 10 mg/g equals 1%.
• mg per serving or per package: common for gummies, tinctures and drinks.
• LOQ / ND: "LOQ" is the limit of quantitation, the smallest amount the lab can reliably measure. "ND" means "not detected" at that limit.

Step 2: Understand delta-9 vs THCA vs total THC

This is the part that ties straight to December 11.

Delta-9 THC is the main intoxicating compound in cannabis. THCA is its raw, acidic form found in the plant. THCA isn't intoxicating by itself, but when it's heated (smoked, vaped or dabbed), it converts into delta-9 THC.

That's why many labs list a Total THC line. It's usually calculated like this:

Total THC = Delta-9 THC + (THCA × 0.877)

The 0.877 accounts for weight lost when THCA converts to delta-9. So a flower with 0.2% delta-9 and 20% THCA has a total THC of about 17.7%.

Under the current rules, hemp is judged mainly on delta-9. Under the new federal definition, total THC is what counts. That's why THCA flower, pre-rolls and concentrates are the products most affected.

Step 3: Check the per-container math

For edibles, drinks and tinctures, look for mg per serving and mg per package. Multiply the per-serving number by servings per package to double-check the label. The new federal cap is 0.4 mg of total THC per container, so most of today's intoxicating hemp gummies and drinks are well over that line. Again, that rule isn't in effect until December 11.

Step 4: Look at the safety screens

A full-panel COA goes beyond potency. Look for sections like:

• Heavy metals: lead, arsenic, cadmium, mercury.
• Pesticides: a long list, ideally showing "ND" or "Pass."
• Residual solvents: especially important for vapes and concentrates like live resin.
• Microbials and mycotoxins: mold, yeast, and bacteria like E. coli and salmonella.

Not every product gets every test, but more is better. "Pass" next to each section is what you want to see.

Step 5: Red flags to watch for

• No lab name or contact info.
• Batch number that doesn't match the package.
• A report that's several years old.
• Numbers that look edited, blurry or cut off.
• Potency on the label that's wildly different from the COA.

If something looks off, ask us. We're happy to pull up a report and go through it with you.

Practice with products we have in stock

Every product page links its lab results where available. Here are a few good ones to practice on, across different formats:

St. Croix Cannabis THCa Flower - THCA flower is the best example of why total THC matters. Look for the THCA %, delta-9 % and the total THC line.

St Croix Cannabis 99.9% Pure THCA Diamonds 1g - Concentrates report potency as a percentage. Compare the COA to the label claim.

Habit THCA Live Rosin Cartridge 1g - A solventless vape. A good one to check for heavy metals and other safety screens.

Sweetleaves 5mg THC Gummies - Edibles are where mg per serving and mg per package come in. Practice the per-container math here.

Mainstream CBD Full Spectrum Tincture - Our own full spectrum CBD. Full spectrum products contain small amounts of other cannabinoids, so look at the whole profile, not just CBD.

FAQ

Where do I find a product's COA?

Check the product page on our site, scan the QR code on the package if it has one, or ask us in store. If you can't find one, reach out and we'll help.

What does "ND" mean on a COA?

"Not detected." The lab didn't find that compound above its limit of quantitation (LOQ). It doesn't always mean exactly zero, just below what the lab can reliably measure.

Why is total THC higher than delta-9 THC?

Because total THC adds in THCA (multiplied by 0.877). THCA converts to delta-9 when heated, so total THC estimates the potential delta-9 after smoking or vaping.

Will the products I buy now still be legal after December 11?

The federal rules change December 11, 2026 unless Congress acts first, and state laws vary. Many of today's intoxicating hemp products would not meet the new federal definition. We'll keep this blog updated as things develop.

Is a COA a guarantee of quality?

It's the best tool you have, but it's only as good as the lab and the match between the batch tested and the product you're holding. Look for an accredited lab, a matching batch number and a recent date.

Questions? Come see us

Want help reading a lab report? Visit Mainstream CBD in Lakeville, MN at 17677 Kenwood Trl. Our team will walk you through it. Or shop anytime at mainstreamcbd.com. Some products are online-only and in-store selection may differ, so check the product page or ask us before you visit.

All products are intended for adults 21+ only. These statements have not been evaluated by the Food and Drug Administration. Products are not intended to diagnose, treat, cure, or prevent any disease. This post is for educational purposes only and is not legal advice. Hemp and cannabis laws vary by state and can change, so please check your local laws before purchasing.