Medical Cannabis for Epilepsy
This page shares evidence-based information about cannabidiol (CBD) and other cannabis-based products in epilepsy care. Medical cannabis is not appropriate for everyone, and it should only be considered with guidance from a neurologist or epilepsy specialist.
What “Medical Cannabis” Means in Epilepsy
“Medical cannabis” is a broad term that can include products containing CBD (cannabidiol), THC (tetrahydrocannabinol), or combinations. In epilepsy care, the best evidence supports prescription-grade purified CBD (cannabidiol oral solution).
Who May Benefit Most?
Cannabis-based therapy is usually discussed when seizures continue despite appropriate trials of anti-seizure medications (often called drug-resistant epilepsy).
- People with drug-resistant epilepsy (seizures persist despite multiple medications)
- Specific epilepsy syndromes where CBD has the strongest evidence (your neurologist can confirm)
- When seizures significantly affect safety, learning, independence, or quality of life
What the Evidence Supports
In Canada, prescription cannabidiol (CBD) has an approved indication as adjunctive therapy for seizures associated with Lennox–Gastaut syndrome (LGS), Dravet syndrome (DS), and tuberous sclerosis complex (TSC) in patients 2 years and older. (This is the prescription product called Epidiolex.)
Types of Cannabis Products and Epilepsy Relevance
| Product Type | What It Means | Relevance to Epilepsy |
|---|---|---|
| Prescription CBD (cannabidiol oral solution) | Standardized pharmaceutical CBD with consistent dosing and monitoring guidance. | Strongest evidence for specific syndromes (LGS, DS, TSC) as adjunctive therapy. |
| CBD-dominant oils (non-prescription) | CBD-rich products from licensed sellers (quality varies by product). | Sometimes used, but dosing consistency and THC content can vary. Must be supervised medically. |
| Balanced CBD:THC oils | Products containing both CBD and THC. | THC can cause psychoactive effects and may worsen seizures for some. Requires extra caution. |
| THC-dominant products | Higher THC products. | Not recommended for seizure control and may increase risks (especially for youth). |
| Inhaled products (vape/flower) | Smoked or inhaled cannabis. | Not appropriate for epilepsy management; difficult to dose consistently and higher risk profile. |
Safety and Monitoring
- Medication interactions: CBD can interact with some anti-seizure medications (your team may adjust doses).
- Liver monitoring: Some patients need bloodwork to monitor liver enzymes, especially with certain medications.
- Side effects: Can include sleepiness, GI upset, appetite changes, or diarrhea. Report changes promptly.
- Seizure tracking: Keep a seizure log to measure benefits and risks over time.
When Extra Caution Is Needed
- Children, teens, and young adults (developing brain + mental health risks with THC)
- Pregnancy or breastfeeding (discuss risks with your care team)
- History of substance use disorder or significant mental health concerns
- People with complex medication regimens (higher interaction risk)
Access in British Columbia
In Canada, medical access typically involves a medical document (authorization) from a physician or nurse practitioner and obtaining products through federally regulated systems. Your provider can guide the safest pathway for your situation.
1) Start with your specialist
Discuss seizure goals, prior medication trials, and whether CBD therapy is appropriate for your epilepsy type.
2) Use regulated sources
Ask about accessing cannabis for medical purposes through Health Canada pathways and regulated sellers.
3) Monitor and adjust
Start low, go slow, and follow up for seizure tracking, side effects, and labs if needed.
Supporting Links
- Health Canada — Cannabis for medical purposes
- Health Canada — How to access cannabis for medical purposes
- HealthLinkBC — Cannabis health information (BC)
- Canadian Paediatric Society — Evidence & recommendations (children)