CBD Oil Achieved Seizure Freedom in 19% of Treatment-Resistant Epilepsy Patients | Research

The takeaway

A standardized 24% CBD oil reduced seizures by at least 50% in 73% of treatment-resistant epilepsy patients, with 19% becoming seizure-free over a 40-month follow-up.

Epilepsy patients, neurologists, parents of children with treatment-resistant epilepsy

19% seizure-free, 73% had 50%+ reduction

What the researchers found

Among 37 patients with treatment-resistant epilepsy of various causes, 7 (19%) became seizure-free and 27 (73%) reported more than 50% seizure reduction at 40-month follow-up. The median achieved CBD dose was 4.2 mg/kg/day. Few significant side effects were reported.

Why it matters

While pharmaceutical CBD (Epidiolex) has been studied in RCTs, data on other CBD formulations are sparse. This study provides real-world evidence that standardized CBD oil can help treatment-resistant patients.

The numbers in context

37 patients; median age 16.1; 19% seizure-free; 73% had >50% improvement; median dose 4.2 mg/kg/day; 60% had epileptic encephalopathy; follow-up 24-72 weeks

How the study worked

Open retrospective study of 37 patients (46% female, median age 16.1 years) with refractory epilepsy receiving add-on therapy with 24% CBD-based oil (sublingual, starting 5-10 mg/kg/day, max 50 mg/kg/day). Follow-up ranged from 24-72 weeks.

What this study cannot tell us

Open retrospective design without placebo control or blinding. Small sample size. Seizure frequency based on caregiver reports.

How to read the evidence

Open retrospective study without controls. Provides encouraging real-world data but cannot establish causation.

When this study was published

Published in 2022

The bigger picture

Patients with treatment-resistant epilepsy have limited options. This study expands the evidence for CBD beyond pharmaceutical formulations to standardized oil preparations with long follow-up.

Questions still open

How does this CBD oil formulation compare to pharmaceutical-grade CBD (Epidiolex) in efficacy? Would the 19% seizure-free rate hold in a randomized controlled trial?

Common questions

How effective was CBD oil for epilepsy?

In this study, 19% of treatment-resistant patients became seizure-free and 73% had at least 50% fewer seizures, using a standardized 24% CBD oil at a median dose of 4.2 mg/kg/day.

What types of epilepsy were treated?

The study included patients with epileptic encephalopathy (60%), focal epilepsy (24%), and generalized epilepsy (16%), all of which had been resistant to previous treatments.

Read the original research

An Open Retrospective Study of a Standardized Cannabidiol Based-Oil in Treatment-Resistant Epilepsy.

Cannabis and cannabinoid research, 7(2), 199-206

View on PubMed ↗Publisher’s paper ↗

Citation

Marchese, Francesca; Vari, Maria Stella; Balagura, Ganna; Riva, Antonella; Salpietro, Vincenzo; Verrotti, Alberto; Citraro, Rita; Lattanzi, Simona; Minetti, Carlo; Russo, Emilio; Striano, Pasquale. (2022). An Open Retrospective Study of a Standardized Cannabidiol Based-Oil in Treatment-Resistant Epilepsy.. Cannabis and cannabinoid research, 7(2), 199-206. https://doi.org/10.1089/can.2019.0082