Last updated: 10 September 2026. Informational only, not medical advice.
CBD and seizure medications carry a documented, well-studied interaction, primarily because CBD itself is an FDA-approved seizure treatment (Epidiolex) and its interactions with other anti-seizure drugs were studied specifically during its approval process. The best-documented interaction is with valproate, which combined with CBD can raise liver enzyme levels, and with clobazam, where CBD raises levels of its active metabolite.
CBD and seizure medications at a glance
| Medication | Documented interaction | Clinical relevance |
|---|---|---|
| Valproate (Depakote) | Combined use associated with liver enzyme elevation | High, monitored in Epidiolex trials |
| Clobazam (Onfi) | CBD raises levels of its active metabolite, norclobazam | High, well documented, often requires dose adjustment |
| Other anti-seizure medications | Variable, depends on specific liver enzyme pathway | Case by case |
Why this interaction is unusually well documented
Unlike many CBD-medication interactions, which are inferred from general enzyme pathway knowledge, the CBD-clobazam and CBD-valproate interactions were specifically studied during Epidiolex’s clinical trials and FDA approval process, since CBD (as Epidiolex) is prescribed alongside other anti-seizure medications for conditions like Dravet syndrome and Lennox-Gastaut syndrome. This means the interaction data here is genuinely clinical, not just theoretical extrapolation from liver enzyme pathways.
The clobazam interaction specifically
CBD inhibits the enzyme that clears norclobazam, clobazam’s active metabolite, leading to significantly elevated norclobazam levels with combined use. This is well-documented enough that patients on both medications are typically monitored, and clobazam dose adjustments are sometimes made specifically to account for this interaction.
The valproate interaction specifically
Combined CBD and valproate use has been associated with elevated liver enzymes in clinical trial monitoring, this is why Epidiolex prescribing information includes specific guidance about liver function monitoring, particularly when combined with valproate.
What this means if you’re on seizure medication
If you have epilepsy or another seizure disorder and take prescription anti-seizure medication, any CBD use, including over-the-counter products, not just Epidiolex, should be discussed directly with your neurologist first. This is genuinely one of the more consequential interaction categories discussed on this site, given both the seizure disorder’s seriousness and the specificity of the documented interactions.
Why over-the-counter CBD isn’t automatically safer
Some people assume that because Epidiolex is the “real” pharmaceutical CBD, over-the-counter CBD products are somehow exempt from these interactions. This isn’t the case, the interacting compound is CBD itself, regardless of whether it comes in an FDA-approved pharmaceutical formulation or a consumer product. The concentration and consistency differ, but the interaction mechanism doesn’t.
Practical guidance
- Never add CBD, including over-the-counter products, to a seizure medication regimen without your neurologist’s direct knowledge
- If on clobazam, expect your doctor to monitor for signs of elevated norclobazam levels (increased sedation is a common sign) if CBD is introduced
- If on valproate, expect liver function monitoring if CBD is added
- Never stop or adjust seizure medication based on CBD use without medical guidance, seizure control is too important to risk
- Report any new symptoms (increased sedation, confusion, unusual fatigue) to your neurologist promptly if using both
Who this applies to most directly
- Anyone on clobazam. Well-documented, clinically significant interaction requiring monitoring.
- Anyone on valproate. Liver enzyme monitoring is relevant if combining with CBD.
- Parents or caregivers of children with seizure disorders. Given complex medication regimens common in pediatric epilepsy, this conversation should happen with the treating neurologist before any CBD product is introduced.
Frequently asked questions
Can I take CBD with my seizure medication?
Possibly, but only with your neurologist’s direct knowledge and guidance, given the well-documented interactions with clobazam and valproate specifically.
Is over-the-counter CBD different from Epidiolex for this interaction?
The interaction mechanism is the same, since it’s CBD itself causing the interaction, not something specific to the pharmaceutical formulation. Consult your neurologist regardless of the CBD source.
What symptoms suggest a clobazam interaction?
Increased sedation or drowsiness beyond your usual baseline is a common sign of elevated norclobazam levels; report this to your neurologist.
Will CBD affect my liver if I’m on valproate?
This combination has been associated with liver enzyme elevation in clinical monitoring; your doctor may want to check liver function if combining them.
Should I stop my seizure medication to try CBD instead?
No, never adjust seizure medication without your neurologist’s guidance. Seizure control is too important to risk through unsupervised changes.
