Medical Cannabis for Epilepsy UK: Epidyolex, Access and Evidence

Epilepsy is one of the few neurological conditions for which cannabis-based medicines are supported by strong clinical evidence — and one of the only areas where NHS prescriptions for cannabinoid products are available in the UK. From Epidyolex on the NHS to specialist private prescriptions for treatment-resistant seizures, this guide covers the full spectrum of cannabis-based epilepsy treatment available to UK patients in 2026.

Epidyolex: The NHS-Licensed CBD Medicine for Epilepsy

Epidyolex (cannabidiol oral solution, GW Pharmaceuticals / Jazz Pharmaceuticals) is a pharmaceutical-grade CBD medicine licensed by the MHRA for two specific epilepsy syndromes:

• Dravet syndrome: A severe, treatment-resistant childhood epilepsy caused in most cases by SCN1A gene mutations
• Lennox-Gastaut syndrome (LGS): A severe childhood epilepsy with multiple seizure types and characteristic slow spike-and-wave EEG pattern

NICE Technology Appraisal TA614 (published 2019, updated 2022) recommends Epidyolex on the NHS for children aged 2 and over with Dravet syndrome or LGS, used alongside clobazam, when other treatments have failed. This makes it one of very few cannabis-based products available through NHS prescription in England, Wales, and Scotland.

Epidyolex contains 100mg/ml CBD and is taken orally twice daily. Clinical trials showed a 39% reduction in convulsive seizure frequency in Dravet patients compared to placebo, and a 42% reduction in drop attacks in LGS patients — both statistically significant and clinically meaningful results.

Sativex and THC-Containing Products for Epilepsy

Sativex (nabiximols — THC:CBD 1:1 oromucosal spray) is licensed in the UK for spasticity in multiple sclerosis, not for epilepsy. However, some specialist epilepsy neurologists prescribe THC-containing products off-label for adult patients with treatment-resistant epilepsy, particularly those with seizure types not covered by Epidyolex.

For adult patients with treatment-resistant focal epilepsy or other syndromes not covered by TA614, private prescriptions for high-CBD, low-THC cannabis oils are available through specialist neurologists at UK cannabis clinics. These are distinct from Epidyolex — they are unlicensed cannabis-based medicinal products (CBMPs) rather than a licensed medicine, and require a Specials licence from the MHRA for import if not domestically produced.

Treatment-Resistant Epilepsy and the NICE Framework

The term treatment-resistant (also called refractory) epilepsy is typically defined as failure of two or more appropriately chosen and tolerated antiseizure medicines (ASMs) to achieve sustained seizure freedom. In the UK, approximately 30% of the estimated 600,000 people with epilepsy have treatment-resistant seizures.

For this group, NICE TA614 provides the most direct pathway to NHS-funded cannabis-based treatment — but only for the specific syndromes covered. For other treatment-resistant epilepsy, the pathway is:

1. Referral to a tertiary epilepsy centre (most UK regions have one)
2. Assessment by an epilepsy specialist neurologist
3. If CBD is deemed appropriate, private prescription for a CBMP oil or consideration of a compassionate use application

The Epilepsy Society and NICE both support careful consideration of cannabis-based options in treatment-resistant cases, provided patients are under specialist care.

CBD-Dominant Products and UK Prescribing

Outside of Epidyolex, UK specialists prescribe CBD-dominant products (e.g., 20:1 CBD:THC or pure CBD oils) for adults with treatment-resistant epilepsy. Key considerations:

• Drug interactions: CBD is a potent inhibitor of CYP2C19 and CYP3A4 enzymes that metabolise several common ASMs including clobazam, valproate, and eslicarbazepine. Dose adjustments are often required, and close monitoring of drug levels is recommended when starting CBD alongside existing ASMs.
• Transaminase monitoring: Epidyolex trials showed elevated liver enzymes (transaminase) in some patients, particularly when co-administered with valproate. Liver function tests should be performed at baseline and periodically during treatment.
• Dosing: For Epidyolex, the recommended dose is 2.5 to 10mg/kg/day in two divided doses. For unlicensed CBD products, specialist neurologists typically titrate slowly from 1 to 2mg/kg/day.

To compare available CBD-dominant products suitable for epilepsy management, browse medical cannabis products by CBD ratio. For specialist neurologist clinics with epilepsy experience, visit the clinic directory. See also the epilepsy condition guide for recommended products and patient resources.

Accessing Medical Cannabis for Epilepsy in Practice

For parents of children with Dravet syndrome or Lennox-Gastaut syndrome, the NHS pathway via NICE TA614 is the appropriate first step — speak to your child's paediatric neurologist about Epidyolex eligibility. For adults with treatment-resistant epilepsy not covered by the NICE guidance, the private specialist route applies.

Several UK cannabis clinics have neurologists on their specialist panels who are experienced in epilepsy prescribing. When seeking a consultation, ensure the clinician has genuine neurology credentials rather than a general practitioner acting outside their specialty area — the CQC enforces this requirement. Bring a detailed seizure diary, your current antiseizure medication list with doses, and any relevant EEG reports or MRI results. The more complete your clinical picture, the better the specialist can assess whether CBD or a balanced CBMP is appropriate alongside your existing regimen. Visit the clinic directory to find specialist neurology clinics, and the conditions page for a full list of conditions treated with medical cannabis in the UK.