Last updated: October 2026
The best-proven benefit of CBD is in medicine: a prescription CBD, Epidyolex, reduces seizures in some rare forms of childhood epilepsy at high doses. For everyday uses like sleep, stress and pain, evidence is small, mixed or mostly negative. Many people use CBD as part of a daily routine. CBD is a food supplement in the UK, not a treatment.
Below: what the research shows for each common use, the side effects, and links to our detailed guides.
CBD benefits: the evidence at a glance
| Use | Strength of evidence | Our detailed guide |
|---|---|---|
| Rare childhood epilepsies | Strong, at prescription doses | Prescription CBD |
| Anxiety in stressful situations | Small trials, high single doses | CBD and anxiety |
| Sleep | Small and mixed | CBD for sleep |
| Pain | Mostly negative in trials | CBD for pain |
| Arthritis | Negative in three trials | CBD for arthritis |
| Focus | Little evidence | CBD and focus |
| Skin | Lab studies; little human evidence | CBD for skin |
| Migraine | CBD alone no better than placebo | CBD for migraines |
| Addiction | Early, small trials at high doses | Is CBD addictive? |
Where CBD is a licensed medicine
Epidyolex is purified CBD licensed in the UK for seizures in Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. In a 2017 trial in Dravet syndrome, monthly convulsive seizures fell from a median of 12.4 to 5.9, against 14.9 to 14.1 on placebo, at 20mg per kg a day. That’s hundreds of times more than a food supplement serving, under specialist care. Researchers have also studied high-dose CBD for psychosis, with early, mixed results. None of this applies to over-the-counter CBD. See medical cannabis in the UK.
Everyday uses: what the research shows
- Stress and anxiety: small trials found single doses of 300 to 600mg reduced anxiety during a public speaking test. Daily low doses haven’t been well studied.
- Sleep: some people find CBD helps them wind down; trials are small, short and mixed.
- Pain: a 2024 review found 15 of 16 placebo-controlled trials showed no benefit.
- Exercise recovery: small, mixed studies. See CBD for athletes.
Surveys show many UK users take CBD for sleep, pain and anxiety. See CBD statistics UK. How people feel matters, but surveys can’t separate CBD from expectation. See what CBD feels like.
Side effects
| Side effect | Notes |
|---|---|
| Drowsiness | More likely at higher doses |
| Diarrhoea and stomach upset | Dose-related |
| Appetite changes | Mainly at prescription doses |
| Raised liver enzymes | Seen at high doses. See CBD and the liver |
| Medicine interactions | See CBD and medication |
Full guide: CBD side effects.
If you want to try CBD
- Choose a product on the FSA public list with a batch lab report.
- Start low and take it consistently for a few weeks. See how to take CBD oil.
- Be wary of any brand claiming CBD treats or cures a condition. See how to avoid CBD scams.
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.
New to CBD? See the complete beginner’s guide.
FAQs
What are the proven benefits of CBD?
The strongest evidence is for prescription CBD in some rare childhood epilepsies. For everyday uses like sleep, stress and pain, evidence is small, mixed or negative.
What does CBD do to the body?
It acts on several targets in the body, mostly weakly at cannabinoid receptors. It doesn’t make you high. See our endocannabinoid system guide.
Is CBD good for anxiety?
Small trials found high single doses reduced anxiety in a public speaking test. CBD isn’t a treatment for anxiety disorders.
Is it safe to take CBD every day?
Many adults do. Start low, keep to a sensible dose, and check with your GP or pharmacist first if you take any medication.
What are the side effects of CBD?
Drowsiness, diarrhoea and appetite changes, mostly at higher doses, plus raised liver enzymes at very high doses and possible medicine interactions.
Sources
- Devinsky O et al. Trial of cannabidiol for drug-resistant seizures in the Dravet syndrome. N Engl J Med, 2017.
- Bergamaschi MM et al. Cannabidiol reduces the anxiety induced by simulated public speaking in treatment-naïve social phobia patients. Neuropsychopharmacology, 2011.
- McGuire P et al. Cannabidiol as an adjunctive therapy in schizophrenia: a multicenter randomized controlled trial. Am J Psychiatry, 2018.
- Moore A et al. Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. J Pain, 2024.
- Electronic Medicines Compendium. Epidyolex: summary of product characteristics.
