THC, CBD, CBN and CBG, and Delta-9 vs. Delta-8: What's the Difference?
What cannabinoids are, how the plant makes them, why labels list THCA and Total THC, and how delta-8-THC differs from delta-9-THC chemically.
The cannabis plant makes more than a hundred related compounds called cannabinoids. Only a handful show up on product labels. This article explains what they are, where they come from, and how to read the numbers.
Where cannabinoids come from
Cannabinoids are made in the plant's trichomes, the tiny resin glands on the flowers. (See how the cannabis plant works for a closer look.) The plant doesn't make THC or CBD directly. It makes them in an acid form first.
- The plant builds CBGA, often called the "mother" cannabinoid.
- Its enzymes turn most of that CBGA into THCA, CBDA or other acids. Which ones, and how much, depends mostly on the plant's genetics.
- Heat turns each acid into its familiar form: THCA becomes THC, CBDA becomes CBD, and CBGA becomes CBG. This step is called decarboxylation.
- Over time, light, air and warmth slowly turn some THC into CBN.
The main ones on our menu
| Cannabinoid | What it is | Where you'll see it |
|---|---|---|
| THCA | The acid form of THC that the plant makes | Flower labels, which often list THCA and THC separately |
| THC (delta-9-THC) | The main cannabinoid in most cannabis | Nearly every product's label |
| CBD | Made by the plant alongside THC, in different amounts from strain to strain | CBD products, and labels with a CBD:THC ratio |
| CBN | Forms as THC ages | Some edibles and tinctures that list it |
| CBG | Made from CBGA; usually present in small amounts in mature plants | Some products that list it |
Why labels say "Total THC"
Because fresh flower holds most of its THC as THCA, a lab report or label often lists both. Total THC estimates how much THC the product could have once heated:
Total THC = THC + (THCA × 0.877)
The 0.877 is there because THCA loses a little weight, as carbon dioxide, when it turns into THC. Products like edibles, tinctures and vapes are made with already-heated oils, so their labels usually show THC directly.
Delta-9 vs. delta-8: a chemistry difference
When people say "THC", they almost always mean delta-9-THC. Delta-8-THC is a close chemical relative. The two have exactly the same atoms. The only difference is where one double bond sits in the molecule: at the ninth carbon in delta-9, and at the eighth in delta-8. That's where the names come from.
Some facts worth knowing:
- The cannabis plant makes only a trace of delta-8-THC naturally.
- Most delta-8 products sold elsewhere are made in a lab, by chemically converting CBD extracted from hemp.
- Its legal status has been debated and varies from state to state.
New Mill sells only regulated medical cannabis products under Maine's medical cannabis program. We don't sell delta-8 products. The THC on our labels is delta-9-THC.
Reading a label at New Mill
On our product pages, edibles, tinctures and drinks show their THC in milligrams, and flower, pre-rolls, concentrates and vapes show their weight. The package label in the store gives the full cannabinoid numbers. Labels may also show CBD, CBN or CBG, and a ratio like 1:1, which means equal amounts of CBD and THC. Our tinctures and edibles article walks through the math on an edible's label.
If you have questions about a specific product, our budtenders can walk you through its label.
New Mill is a medical cannabis dispensary in Bethel, Maine, serving qualifying patients 18 and older from Maine or another state, with a valid medical cannabis certification and photo ID from the same state. This article is general information about the chemistry of cannabis, not medical advice.