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

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.

Marchese, Francesca et al.·Cannabis and cannabinoid research·2022·Moderate EvidenceRetrospective Cohort
RTHC-04038Retrospective CohortModerate Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Retrospective Cohort
Evidence
Moderate Evidence
Sample
N=37

What This Study 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.

Key Numbers

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 They Did This

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.

Why This Research 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 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.

What This Study Doesn't Tell Us

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

Questions This Raises

  • ?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?

Trust & Context

Key Stat:
19% seizure-free, 73% had 50%+ reduction
Evidence Grade:
Open retrospective study without controls. Provides encouraging real-world data but cannot establish causation.
Study Age:
Published in 2022
Original Title:
An Open Retrospective Study of a Standardized Cannabidiol Based-Oil in Treatment-Resistant Epilepsy.
Published In:
Cannabis and cannabinoid research, 7(2), 199-206 (2022)
Database ID:
RTHC-04038

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Looks back at existing records to find patterns.

What do these levels mean? →

Frequently Asked 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 More on RethinkTHC

Cite This Study

RTHC-04038·https://rethinkthc.com/research/RTHC-04038

APA

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

MLA

Marchese, Francesca, et al. "An Open Retrospective Study of a Standardized Cannabidiol Based-Oil in Treatment-Resistant Epilepsy.." Cannabis and cannabinoid research, 2022. https://doi.org/10.1089/can.2019.0082

RethinkTHC

RethinkTHC Research Database. "An Open Retrospective Study of a Standardized Cannabidiol Ba..." RTHC-04038. Retrieved from https://rethinkthc.com/research/marchese-2022-an-open-retrospective-study

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.