What happens when you take cbd with valproate?
Valproate (valproic acid, divalproex sodium) is a broad-spectrum anti-seizure medicine also used for migraine prevention and bipolar disorder. CBD (cannabidiol) is the active molecule in prescription Epidiolex and in over-the-counter hemp products. Both independently put stress on the liver, and combining them is one of the better-documented interactions on the Epidiolex label.
- Valproate stresses the liver on its own. It is well known to cause liver enzyme elevation, rare serious liver injury, and high blood ammonia (hyperammonemia) that can occur even when liver enzymes look normal.
- CBD carries its own liver signal. In clinical trials, CBD produced liver transaminase (ALT/AST) elevations, and the FDA label includes a dedicated warning on hepatocellular injury.
- Together the liver signal climbs sharply. When CBD and valproate are taken at the same time, the rate of clinically meaningful ALT/AST elevation rises markedly compared with either drug alone.
- Ammonia can rise too. Postmarketing reports describe elevated ammonia in CBD-treated patients, most often when valproate, clobazam, or both are also on board. This can happen with only modest changes in liver enzymes.
- The effect tracks with how much CBD is taken. Higher CBD exposure is associated with a higher chance of enzyme elevation, so dose and product choice matter.
Why is this important?
The patients most likely to be offered CBD are often already on valproate — refractory epilepsy syndromes such as Lennox-Gastaut, Dravet, and tuberous sclerosis complex are typical indications for both. That makes the pairing common and predictable rather than exotic.
Most enzyme elevations are without symptoms and reverse when the dose is reduced or stopped, but a minority progress and a small number become serious. Hyperammonemic encephalopathy is the part that catches people off guard: it can appear with only modest liver-enzyme changes and shows up as new confusion, lethargy, or unexplained worsening of seizure control — easily mistaken for the underlying epilepsy getting worse.
The risk extends to over-the-counter CBD. Many patients and parents use consumer CBD oils for breakthrough symptoms without telling the neurologist, assuming that hemp products are not real drugs. The signal is dose-related, so modest consumer doses are likely lower risk than high-dose prescription CBD — but it is not zero risk, and the combination deserves lab monitoring regardless of the source.
What should you do?
This combination should be managed by the prescribing neurologist with structured liver monitoring. Here is how to think about the timing.
Before any change (starting valproate, or adding CBD to valproate):
- Tell the prescriber about all CBD use — prescription and over-the-counter — before you start.
- Get baseline liver tests (ALT, AST, alkaline phosphatase, total bilirubin) before starting either drug.
- Do not add any CBD product to valproate on your own initiative.
Every day while on the combination:
- Watch for symptoms of liver injury: jaundice, dark urine, right-upper-abdomen pain, unusual fatigue, loss of appetite, or nausea.
- Watch for signs of high ammonia: new confusion, lethargy, vomiting, or unexplained worsening of seizures.
- Avoid stacking other liver stressors — alcohol, frequent high-dose acetaminophen, and unregulated bodybuilding or herbal liver-stressing supplements (kava, comfrey, chaparral).
After any change (starting or increasing a dose):
- Have repeat liver enzyme testing on the schedule your prescriber sets after initiation or any dose increase.
- Have an ammonia level checked if new confusion, lethargy, vomiting, or worsening seizures appear — even if liver enzymes look reasonable.
- If liver tests rise meaningfully, or symptoms of liver injury appear, contact the prescriber right away; they may reduce or stop one of the drugs.
Be especially cautious if clobazam is also part of the regimen, since it appears to add to the ammonia signal. Doses and exact thresholds should be reviewed with your doctor or pharmacist rather than self-managed.
Which specific products are affected?
Valproate is sold as Depakote, Depakote ER, Depakene, Depacon (injectable), Stavzor, Epilim, and many generics. The divalproex, valproic acid, and valproate sodium forms all behave the same way for this interaction.
On the CBD side, the interaction is best characterized for prescription Epidiolex (cannabidiol oral solution), but consumer CBD products — tinctures, gummies, capsules, and vapes — contain the same active molecule and share the mechanism. Full-spectrum hemp products that also contain THC add their own load on liver metabolism. Triple therapy with clobazam plus CBD plus valproate appears to compound the ammonia risk and warrants particularly close monitoring.
The science behind it
The FDA/DailyMed prescribing information for EPIDIOLEX (cannabidiol) is the primary, authoritative source for this interaction. Its Warnings and Precautions section documents hepatocellular injury, reports a clearly higher rate of ALT elevations above three times the upper limit of normal in patients taking concomitant valproate compared with patients on neither drug, and describes postmarketing hyperammonemia occurring mainly in patients also taking valproate or clobazam. The label also notes that the liver signal is dose-related.
This is regulatory-grade evidence drawn from pooled controlled trials plus postmarketing surveillance, which is why the interaction is rated high severity. The independent re-grounding confirmed the existing claim matches the live label.
References:
- FDA/DailyMed EPIDIOLEX (cannabidiol) oral solution prescribing information — Warnings and Precautions, Hepatocellular Injury and Hyperammonemia (setid 8bf27097-4870-43fb-94f0-f3d0871d1eec). DailyMed
Frequently Asked Questions
Can I take CBD if I am on valproate?
Only with your neurologist's involvement. The combination meaningfully raises the chance of liver enzyme elevations and can cause high blood ammonia, so it should not be started on your own — and it needs baseline and follow-up liver testing.
Does over-the-counter CBD count, or only prescription Epidiolex?
It counts. Consumer tinctures, gummies, capsules, and vapes contain the same active molecule and share the mechanism. Modest consumer doses are likely lower risk than high-dose prescription CBD, but the risk is not zero — tell your prescriber about every product.
What symptoms should make me call my doctor?
Jaundice (yellow skin or eyes), dark urine, right-upper-abdomen pain, unusual fatigue, loss of appetite, or nausea — and separately, new confusion, lethargy, vomiting, or unexplained worsening of seizures, which can signal high ammonia.
Can high ammonia happen even if my liver tests are fine?
Yes. Hyperammonemic encephalopathy can occur with only modest liver-enzyme changes, which is why new confusion or worsening seizures should prompt an ammonia check rather than being assumed to be the epilepsy itself.
Does the dose of CBD matter?
Yes. The liver signal is dose-related — higher CBD exposure carries a higher chance of enzyme elevation. The exact amounts and monitoring schedule should be set with your doctor or pharmacist.
Is clobazam relevant here?
Yes. When clobazam is taken alongside CBD and valproate, the ammonia signal appears to be greater, so this three-drug combination warrants particularly close monitoring.
Key takeaways
- Combining CBD with valproate raises the chance of liver enzyme elevations well above either drug alone, and the FDA Epidiolex label documents this directly.
- The combination can also raise blood ammonia, sometimes causing confusion or worsening seizures even when liver tests look only mildly off.
- This applies to over-the-counter CBD too, not just prescription Epidiolex — disclose every product.
- Manage it with neurologist oversight: baseline liver tests, follow-up testing after any change, and prompt review of warning symptoms.
- Concurrent clobazam adds risk; do not self-adjust doses — review with your doctor or pharmacist.