Hemp and marijuana are the same plant species — Cannabis sativa. The only legal difference is THC content: hemp is defined by U.S. law as cannabis with 0.3% or less delta-9 THC on a dry weight basis, and anything above that line is marijuana. The CBD molecule itself is identical either way, and once it's purified into isolate it tests at 0% THC no matter which plant it came from.
Where the line is drawn
Congress drew the hemp/marijuana line in the 2018 Farm Bill, which removed hemp — cannabis with no more than 0.3% delta-9 THC — from the definition of marijuana in the Controlled Substances Act. That one number, measured by dry weight, determines whether a plant is a federally legal agricultural crop or a federally controlled substance. It's a legal classification, not a botanical one: hemp and marijuana are the same species and can even be the same strain grown under different conditions.
Hemp vs marijuana at a glance
| Hemp | Marijuana | |
|---|---|---|
| Species | Cannabis sativa | Cannabis sativa |
| Delta-9 THC (dry weight) | ≤ 0.3% (federally legal) | > 0.3% (federally illegal) |
| CBD content | Typically higher per plant | Varies widely by strain |
| Legal status (federal) | Legal agricultural commodity | Schedule I controlled substance |
| CBD after purification | Identical isolate — 0% THC, same molecule | |
Why "hemp-derived" appears on every label
If a CBD product is labeled "hemp-derived," it's telling you the source plant tested at or below the 0.3% THC threshold — which is what makes the product federally legal to sell and ship. Marijuana-derived CBD exists mostly in states with legal cannabis programs and carries the same molecule, usually at a much higher price per milligram because of the regulatory overhead.
What this means for your wallet
- Purification erases the difference. Isolate from hemp and isolate from marijuana are chemically the same 0% THC product. The plant source mostly affects the label, not the molecule.
- Hemp isolate is dramatically cheaper. Hemp is an agricultural commodity grown at scale; marijuana-derived CBD carries cannabis-industry pricing. Store tinctures run $0.10–0.20/mg either way — raw economics, not plant source, drive that markup.
- Isolate is the 0% THC choice. If you want to be sure there's no THC in what you're using, isolate is tested at zero — not "under a legal limit." See how that compares in our isolate vs full-spectrum breakdown.