CBD reduces seizures in treatment resistant epilepsy patients

This study examined the effects of CBD on treatment-resistant epilepsy (TRE) and was published in the journal Epilepsia in May 2023. They used the FDA-approved CBD brand Epidiolex.

892 patients were given Epidiolex made by GW Research (part of Jazz Pharmaceuticals). EPIDIOLEX (cannabidiol or CBD) is an oral solution with CBD content of 100 mg/mL. It consists of CBD isolate combined with inactive ingredients that include dehydrated alcohol, sesame seed oil, strawberry flavor, and sucralose.

The starting dose was 2–10 mg/kg/day and gradually increased until a tolerability limit was established up to a maximum of 25–50 mg/kg/day. 

Daily dose range examples for a 150 lb (68kg) person:

  • Start: 2- 10 mg/kg/day is a daily dose of 135mg to 680 mg
  • Maximum: 25-50 mg/kg/day is a daily dose of 1,700 mg to 3,400 mg


Patients were seen by a healthcare practitioner every 2–4 weeks for the first 4 months, and every 2–12 weeks afterwards for a median of 694 days. The patients' average age was 12, however they ranged from less than 1 to 75 years old. All patients enrolled were shown to be treatment-resistant to at least 2 different types of standard epilepsy treatments.

The results in the authors' words:

reductions in convulsive seizure type frequency ranged from 47% to 100%, which included median reductions of 58%–100% in clonic seizures and 77%–96% in atonic seizures.

Reductions in nonconvulsive seizure types ranged from 50% to 100%, which included median reductions of 95%–100% in absence (typical and atypical) seizures;

reductions in epileptic spasms ranged from 80% to 95%. 

CBD was well tolerated, and adverse events were consistent with previous findings. 


Their conclusions:

Approximately 50% of patients had ≥50% [at least 50%] reduction in convulsive and nonconvulsive seizure types and epileptic spasms at nearly all intervals.

These results show a favorable effect of long-term CBD use in patients with TRE, who may experience various convulsive and nonconvulsive seizure types.


The full text article is here at the Wiley Online Library.