Last updated: October 2026
CBD and THC are both cannabinoids from the cannabis plant, but THC makes you high and CBD doesn’t. In the UK, THC is a controlled Class B drug, while CBD is legal in food supplements that meet the rules. THC also impairs driving and shows up on drug tests.
Below: a side-by-side comparison, effects, legal status, drug tests, driving, medicines that use them, and how to avoid THC.
CBD vs THC at a glance
| CBD (cannabidiol) | THC (tetrahydrocannabinol) | |
|---|---|---|
| Gets you high? | No | Yes |
| UK legal status | Legal in compliant food supplements | Controlled, Class B |
| Addictive? | No evidence of abuse potential | Can cause dependence |
| Driving | Didn’t impair driving in a 2020 trial; avoid if drowsy | Impairs driving; illegal above a very low blood limit |
| Drug tests | Not usually tested for | The main thing tests look for |
| Main source | Hemp | Drug-type cannabis |
How they affect you
THC strongly activates CB1 receptors in the brain, which causes the high, changes in perception, appetite and memory, and sometimes anxiety or paranoia. FRANK warns that regular cannabis use can lead to dependence and, in some people, mental health problems. CBD binds only weakly to CB1 and acts on several other targets, so it doesn’t change your state of mind. In trials, even large doses of CBD felt like a placebo. See does CBD get you high?, what CBD feels like and the endocannabinoid system.
UK law
Cannabis and THC are Class B drugs. CBD itself isn’t controlled, but CBD products must contain no more than tiny traces of THC, and CBD food products must be linked to an application on the FSA’s public list. Hemp can be grown only under a Home Office licence. See is CBD legal in the UK? and hemp vs marijuana.
Drug tests and driving
- Drug tests look for THC and its breakdown products, not CBD. A CBD product containing traces of THC could still cause a positive result. See CBD and drug tests.
- Driving: it’s illegal to drive with certain levels of illegal drugs, including cannabis, in your blood, even if your driving seems fine. Police can use roadside kits that screen for cannabis. A 2020 on-road trial found CBD-dominant cannabis didn’t impair driving, while THC did. Don’t drive if any product makes you drowsy. See CBD and driving.
Medicines that use CBD and THC
| Medicine | Contains | Licensed in the UK for |
|---|---|---|
| Epidyolex | Purified CBD | Seizures in some rare forms of epilepsy |
| Sativex | THC and CBD spray | Muscle spasticity in multiple sclerosis |
| Nabilone | A synthetic THC-like drug | Nausea from chemotherapy |
These are prescription medicines at much higher doses than supplements. See medical cannabis UK and prescription CBD.
How to avoid THC
- Choose broad spectrum or isolate, not full spectrum. See full vs broad spectrum.
- Check the batch lab report shows THC as not detected. See how to read a lab report.
- Buy from FSA-listed UK products, not unregulated imports.
Our CBD oils and capsules are broad spectrum and on the FSA public list. The FSA’s 10mg a day figure is precautionary advice rather than a legal limit, set while longer-term safety research continues. At Evopure we think it is a very cautious figure, and many adults use more. If you go above it, increase slowly, and check with your GP or pharmacist first if you take any medication. We don’t recommend our products during pregnancy or breastfeeding.
For the full picture, see what is CBD? The complete UK guide.
FAQs
What is the difference between CBD and THC?
THC is intoxicating and a controlled drug in the UK. CBD isn’t intoxicating and is legal in compliant food supplements.
Does CBD contain THC?
Full spectrum products contain some THC. Broad spectrum and isolate have THC removed to non-detectable levels. UK products may contain only tiny traces.
Will CBD show up on a drug test?
Tests look for THC, not CBD, but a product with traces of THC could cause a positive result.
Can I drive after taking CBD?
CBD on its own didn’t impair driving in a 2020 trial, but don’t drive if you feel drowsy, and avoid products containing THC.
Is THC legal in the UK?
No. THC is a Class B drug. It’s only available in specific prescription medicines.
Sources
- Arkell TR et al. Effect of cannabidiol and THC on driving performance: a randomized clinical trial. JAMA, 2020.
- Babalonis S et al. Oral cannabidiol does not produce a signal for abuse liability in frequent marijuana smokers. Drug Alcohol Depend, 2017.
- GOV.UK. Drugs and driving: the law.
- FRANK. Cannabis.
- legislation.gov.uk. Misuse of Drugs Act 1971, Schedule 2.
