Medical marijuana, specifically cannabidiol (CBD), has been shown to help some people with seizure disorders. While one option is FDA-approved, studies have used a variety of cannabis delivery options.

Evidence and FDA Approval

• Epidiolex, a purified CBD oral solution, is FDA-approved for certain severe forms of epilepsy, including:
  • • Dravet syndrome
  • • Lennox-Gastaut syndrome
  • • Tuberous Sclerosis Complex
    

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• • This approval came after clinical trials showed significant seizure reduction in many patients.
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• • THC (tetrahydrocannabinol), the psychoactive part of marijuana, has not been proven effective for seizure disorders and may, in some cases, worsen them.
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How it works

CBD interacts with the endocannabinoid system and other brain signaling pathways. While the exact mechanism isn’t fully understood, it appears to reduce abnormal electrical activity in the brain that can trigger seizures.

What research shows

• Studies show that CBD can reduce seizure frequency by 30–50% in some patients with drug-resistant epilepsy.

• Not everyone responds, and some still need additional anti-seizure medications.

The following are several studies and reviews showing that medical marijuana, especially cannabidiol (CBD), can help in certain seizure disorders. 

Key Studies & Findings

Randomized, dose-ranging safety trial of cannabidiol in Dravet syndrome (children 4–10 years old). This trial showed that various doses of CBD (5, 10, 20 mg/kg/day) were generally well tolerated and helped reduce convulsive seizures versus placebo. (American Academy of Neurology)

Meta-analysis: “Efficacy and Safety of Cannabidiol in Epilepsy: A Systematic Review and Meta-Analysis” identified 4 RCTs (about 550 patients) in LGS and DS. Findings included ~19-20% greater reduction in seizure frequency in CBD groups versus placebo, and the proportion of patients getting ≥ 50% seizure reduction was significantly higher in CBD groups. (PubMed)

Subgroup analyses & interactions: Cannabidiol in conjunction with clobazam (another anti-epileptic drug): a pooled analysis from multiple phase 3 trials in LGS and DS showed that patients receiving both CBD and clobazam had a greater seizure reduction than those not on clobazam. Adverse effects increased, especially sedation/somnolence. (PubMed)

Real-world/observational studies “Observational study of medical marijuana as a treatment for treatment-resistant epilepsies” (29 subjects aged 12-46) using cannabis formulations combining THC and CBD (ratios like 1:20 or 1:50, max 6 mg THC/day), treated for ≥ 24 weeks. The study showed no significant difference in convulsive seizure frequency during treatment compared to baseline, and no improvements in other seizure or related measures. So the results were mixed in this case. (PubMed)

Another recent study (2025) among pediatric patients with treatment-resistant epilepsy treated with Epidiolex showed a median reduction in monthly seizures from 30 to 8; about 49% had more than 25% reduction, and 21% had 51–75% reduction. (NORML)

Risks and side effects

• Possible side effects include sleepiness, diarrhea, decreased appetite, and interactions with other seizure medicines.

• Medical marijuana products vary widely in quality; consistency is crucial for seizure treatment.

Summary

CBD (medical marijuana component) can help with certain seizure disorders, especially when standard treatments don’t work. But it should only be used under the guidance of a licensed physician. If you’re ready to try medical marijuana, click the button below to get started or contact us to speak with a health specialist.