The prescription CBD label: it raises active clobazam, raises liver enzymes with valproate, and adds to alcohol
Epidiolex's label: cannabidiol "increases plasma concentrations of N-desmethylclobazam, the active metabolite of clobazam"; with valproate it "increases the incidence of liver enzyme elevations"; with alcohol, more sedation.
Reasonable evidence with real limitations. how we score evidence
Caveat on this rating: The label describes prescription cannabidiol at epilepsy doses (commonly 10 to 20 mg/kg/day); over-the-counter products deliver far less and often not what the packet says, so extrapolation to them is uncertain in both directions.
CBD is sold everywhere without a prescription. The one CBD product with an FDA label is the only place its interactions are written down by a regulator.
Significant findings
EPIDIOLEX (cannabidiol) prescribing information (Jazz, June 2026), Drug Interactions summary: "Consider a dose reduction of substrates of CYP1A2, CYP2C8, UGT1A9, and orally administered P-gp substrates" and "Consider dose modification of CYP2B6 or CYP2C19 substrates." Rifampin, a strong enzyme inducer, cut cannabidiol and its active metabolite by "approximately 32% and 63%".
Section 7.2 on clobazam, a benzodiazepine used for epilepsy: "Concomitant use of EPIDIOLEX with clobazam increases plasma concentrations of N-desmethylclobazam, the active metabolite of clobazam, which may increase the risk of clobazam-related adverse reactions. Consider a reduction in dosage of clobazam if adverse reactions known to occur with clobazam are experienced".
Section 7.3: "Concomitant use of EPIDIOLEX and valproate increases the incidence of liver enzyme elevations. If such elevations occur, consider discontinuation or reduction of EPIDIOLEX and/or concomitant valproate." Section 7.4: "Concomitant use of EPIDIOLEX with other CNS depressants (including alcohol) may increase the risk of sedation and somnolence".
Worth asking
The enzymes on this list, CYP2C19 and CYP1A2 among them, also clear citalopram, escitalopram, clozapine, olanzapine and some benzodiazepines. Whether a gummy or a tincture reaches the doses that produced these effects in epilepsy trials is not stated on the label and has not been measured; the label is about a prescription product at prescription doses. If you use CBD and take valproate, a benzodiazepine or an antipsychotic, the honest position is that a regulator has documented the mechanism and nobody has measured it at your dose, which is a reason to tell the prescriber, not to assume it is nothing.
Source
EPIDIOLEX (cannabidiol) oral solution: FDA-approved prescribing information, Drug Interactions 7.1 to 7.4 — Jazz Pharmaceuticals, Inc.; US Food and Drug Administration (2026)
Regulator or national health body
How this was scored
- Study design
- Regulatory safety determination
- Funding
- Industry funded
- Published in
- Regulator or national health body
- Sample size
- not recorded
- Preregistered
- not recorded
- Conflicts disclosed
- not recorded
- Independent of proponent
- not recorded
- Retracted
- No
Read the full scoring rubric, including what it can't tell you.
Published September 21, 2026.
Questions
How strong is the evidence behind this?
veisund rates this source "moderate evidence". Reasonable evidence with real limitations. It scores 57 out of 100 on our published rubric. One caveat travels with that badge: The label describes prescription cannabidiol at epilepsy doses (commonly 10 to 20 mg/kg/day); over-the-counter products deliver far less and often not what the packet says, so extrapolation to them is uncertain in both directions. The score is calculated from recorded facts about the source — study design, funding, publication venue, sample size, preregistration — not typed in by an editor.
What is the source for this?
EPIDIOLEX (cannabidiol) oral solution: FDA-approved prescribing information, Drug Interactions 7.1 to 7.4 — Jazz Pharmaceuticals, Inc.; US Food and Drug Administration (2026). Published in: Regulator or national health body. The full source is linked on this page so you can read it yourself.
Who paid for this research, and does that matter?
Study design: Regulatory safety determination. Funding: Industry funded. Independence from the proponent is not recorded. Industry sponsorship is one of the most reliably measured biases in medicine, which is why funding carries real weight in the score rather than sitting in a footnote.
Is this medical advice?
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.
This is information to bring to your prescriber, not medical advice and not a reason to change anything on your own. Nothing here is an instruction to stop or reduce a medication. If you are in crisis, call or text 988.