Cannabis produces more than a hundred cannabinoids. Two get almost all the attention, a handful appear on most certificates of analysis, and the rest are present in quantities too small to matter for most purposes.
Understanding what each one is — and particularly the difference between the acidic and neutral forms — makes a potency report considerably easier to read.
What a Cannabinoid Is
Cannabinoids are a family of compounds produced mainly in the trichomes, the resin glands concentrated on cannabis flowers. They share a common biosynthetic origin: the plant produces CBGA, and enzymes convert it into the acidic precursors of the other major cannabinoids.
That single fact explains a lot about cannabis chemistry. CBGA is the branch point. How much goes down each pathway is genetically determined, which is why cultivars differ predictably in cannabinoid profile — and why genetics constrain what a plant can produce regardless of how it is grown.
The Acidic Forms Come First
This is the part most product labels obscure.
A living cannabis plant does not contain meaningful quantities of THC. It contains THCA — tetrahydrocannabinolic acid — which is not intoxicating. THCA converts to THC through decarboxylation, a reaction driven by heat and, more slowly, by time.
The same applies across the family: CBDA becomes CBD, CBGA becomes CBG, and so on. Smoking, vaporising or baking drives the conversion. Eating raw cannabis largely does not.
Laboratories measure both forms and report them separately, which is why a certificate lists THC and THCA as distinct lines. Total THC is then calculated to account for the conversion, using a factor derived from the difference in molecular weight — roughly 0.877.
Two things follow. First, total THC will not equal the THC line on the report; it is a calculated figure. Second, it assumes complete conversion, which real-world heating does not achieve. The reported total is a theoretical maximum rather than what a consumer actually receives. More in THC percentage explained.
The Major Cannabinoids
THC (delta-9-tetrahydrocannabinol)
The compound responsible for cannabis’s intoxicating effects, acting primarily at CB1 receptors concentrated in the central nervous system. It is the most studied cannabinoid and the one every regulatory framework is built around — the 0.3% delta-9 THC threshold is what legally separates hemp from marijuana.
CBD (cannabidiol)
Non-intoxicating, and the second most studied. CBD interacts with the endocannabinoid system differently from THC — it does not bind strongly to CB1 in the way THC does, and much of its activity involves other receptor systems entirely.
It is the only cannabinoid with an approved pharmaceutical formulation in the United States, for specific severe epilepsy syndromes. That approval is narrow and does not extend to the claims made across the retail CBD market.
CBG (cannabigerol)
The neutral form of the precursor from which the others derive. Because most CBGA is converted during growth, mature plants usually contain little CBG — which is why CBG-dominant cultivars are deliberately bred and why CBG products are more expensive.
CBN (cannabinol)
CBN is largely a degradation product. THC oxidises to CBN with exposure to heat, light and oxygen over time, so an elevated CBN figure alongside reduced THC generally indicates age or poor storage rather than genetics.
That makes CBN a useful data point on a certificate. It is an indirect read on how the material was handled — see how to store cannabis properly.
CBC (cannabichromene)
Present in small quantities in most cultivars, non-intoxicating, and considerably less studied than the compounds above.
Delta-8 and the Hemp-Derived Cannabinoids
Delta-8-THC is an isomer of delta-9 — the same atoms arranged slightly differently, with reportedly milder intoxicating effects.
It occurs naturally in trace amounts, far too little to extract economically. Commercial delta-8 is almost always produced by chemically converting CBD, which sits in a legal grey area created by the hemp threshold in the 2018 Farm Bill.
From a testing perspective the concern is straightforward: chemical conversion can leave reaction by-products and residual reagents that standard cannabis panels were not designed to detect. The same applies to other semi-synthetic hemp-derived cannabinoids that have appeared on the market. This is one of the gaps discussed in the limits of current testing methods.
How Laboratories Measure Them
Cannabinoid quantification is done by high-performance liquid chromatography. The choice of HPLC over gas chromatography is deliberate: gas chromatography introduces heat, which would decarboxylate the acidic cannabinoids during the analysis and report a composition the sample never had.
The process separates compounds in solution, detects each as it elutes, and quantifies against calibrated reference standards. Results are reported as a percentage by weight for flower and concentrates, and in milligrams per serving and per package for infused products. See potency testing and the testing process.
Reading a Cannabinoid Profile
A few habits make the profile more useful.
- Look at THC and THCA separately, not only at total THC. The ratio tells you something about the product’s state.
- Check CBN. Elevated CBN with depressed THC suggests age or heat exposure.
- Note which minors were quantified. A panel reporting only THC and CBD is a narrower analysis than one covering the full set.
- Check the basis. Potency reported on a dry-weight basis differs from as-received, and the two are not comparable.
- Do not read potency as quality. It is a concentration measurement, nothing more.
Cannabinoids Are Only Part of the Profile
Two products with identical cannabinoid figures can behave quite differently, and cannabinoid content alone does not explain that.
Terpenes — the volatile aromatic compounds that give cultivars their smell — vary independently of cannabinoid content and are the other half of a chemical profile. How they interact with cannabinoids is covered in terpenes and the entourage effect, and how all of it interacts with human physiology in the endocannabinoid system.