Last updated: October 2026
Prescription CBD in the UK means Epidyolex, a licensed medicine for rare forms of epilepsy, taken at doses often 50 times or more what’s in a shop-bought CBD product. Over-the-counter CBD is sold as a food supplement and can’t make medical claims. Neither is “better”: they’re different products for different purposes, regulated in different ways.
Below: a side-by-side comparison, how the doses compare, what the evidence covers, who can get prescription CBD, and how to choose a good over-the-counter product.
Prescription vs over-the-counter CBD
| Prescription CBD (Epidyolex) | Over-the-counter CBD | |
|---|---|---|
| Legal status | Licensed medicine (MHRA) | Food supplement (FSA novel food) |
| Who decides | A specialist doctor | You |
| Used for | Seizures in Lennox-Gastaut syndrome, Dravet syndrome and tuberous sclerosis complex | General wellbeing; no medical claims allowed |
| Typical daily amount | 5 to 20mg per kg of body weight (hundreds of mg) | FSA advises up to 10mg for healthy adults |
| Form | Purified CBD oral solution | Oils, capsules, balms; broad spectrum, full spectrum or isolate |
| Monitoring | Regular blood tests, including liver function | None |
| Cost | Free on the NHS when prescribed | You pay |
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View productHow the doses compare
Epidyolex is dosed by body weight. For a 60kg adult, 10mg per kg is 600mg of CBD a day, sixty times the FSA’s 10mg figure for supplements. That’s why side effects such as sleepiness, reduced appetite, diarrhoea and raised liver enzymes are common with prescription CBD, and why patients have regular blood tests.
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. See how much CBD to take.
What the evidence covers
Epidyolex was licensed after large clinical trials showed it reduced seizures in specific rare epilepsies. Those results apply to that medicine, at those doses, in those conditions. They don’t show that a low-dose CBD supplement treats epilepsy or anything else.
For over-the-counter CBD at everyday amounts, research is much more limited. Many people use it as part of a calming evening routine. See CBD for sleep and CBD for anxiety for what the research shows.
Never swap a prescribed medicine for a CBD supplement.
Who can get prescription CBD?
On the NHS, Epidyolex is prescribed by specialists for the three epilepsy syndromes above. Private clinics can prescribe cannabis-based medicines, sometimes CBD-only, for other conditions such as chronic pain or anxiety, usually after standard treatments haven’t worked. See medical cannabis in the UK.
Choosing a good over-the-counter CBD
- FSA public list: CBD food products must be linked to an application on it.
- Batch lab report: confirms the CBD content and that THC isn’t detected. See how to read a lab report.
- Clear labelling: mg of CBD per bottle and per serving.
- No medical claims: a brand saying its product treats a condition is breaking UK rules.
- Check interactions with a pharmacist if you take medicines. See can CBD interact with medication?
More in how to choose a CBD oil in the UK.
See also CBD oil vs medical cannabis for pain.
See also is CBD legal in the UK? Our full guide to UK CBD law.
Melatonin follows a similar split between medicine and supplement rules: see melatonin UK guide.
Related guides
- For MS specifically, see what dose of CBD for MS, and how Sativex is prescribed.
- For an at-a-glance table of where the evidence for CBD is strong and where it is still early, see CBD benefits: what the research shows.
- Most interaction data comes from prescription CBD. For how it applies to a course of antibiotics, see CBD and antibiotics.
- Most of what we know about CBD side effects comes from prescription doses like these.
- No CBD medicine is licensed for Parkinson’s in the UK; our guide explains what the Parkinson’s trials have found.
- Another cannabinoid, CBDV, has also been tested in epilepsy; read what the CBDV trials found.
Sources 5
- NHS. Medical cannabis (and cannabis oils).
- emc. Epidyolex 100mg/ml oral solution: summary of product characteristics.
- NICE. Cannabidiol for treating seizures caused by tuberous sclerosis complex (TA873).
- GOV.UK. FSA consumer advice on CBD.
- Food Standards Agency. Cannabidiol (CBD) guidance for businesses.
