The short answer
Valerian may add to the drowsiness clozapine already causes. Federal safety guidance advises against combining valerian with sedatives, so discuss it with the clozapine team before using it. The exact risk is not measured, and taking the products a few hours apart has not been shown to prevent it.
What this answer covers
Valeriana officinalis root and rhizome preparations taken by mouth; blends and other valerian species are not equivalent.
- Supplement or preparation
- Valeriana officinalis
- Medication ingredient
- clozapine
Why the combination deserves care
Clozapine can cause sleepiness and impaired coordination. Valerian safety guidance describes mental dullness and advises against use with sedatives because sleep-inducing effects are possible. Together, these sources support a precaution, but do not show how often extra sedation occurs with clozapine.
What the trial did and did not show
A trial involving 391 people assigned participants to valerian, kava or placebo for four weeks. Valerian did not relieve insomnia more than placebo. That result does not prove that valerian has no effect on alertness, and the trial did not establish whether it changes clozapine safety.
Check the actual product
The relevant botanical is Valeriana officinalis, usually supplied as root or rhizome preparations. A blend containing several sleep ingredients is a different exposure. Show the prescribing team the label and dose so that other sedating ingredients and medicines can be considered.
Spacing is not an established solution
No source here establishes a safe interval between valerian and clozapine. Get advice before adding valerian, and avoid driving or hazardous tasks if drowsy or impaired. Do not alter clozapine dosing to make room for a sleep supplement.
Evidence and practical considerations
Side effects & toxicity
An indirect precaution is warranted because clozapine causes sedation and valerian guidance advises against combining it with sedatives.
- Exact scope
- Valeriana officinalis root and rhizome preparations taken by mouth; blends and other valerian species are not equivalent. with Oral clozapine, RxNorm 2626 IN.
- Medication form and route
- oral clozapine; oral botanical preparation
What remains uncertain
- Not a direct clozapine interaction trial or evidence of severe respiratory depression.
Factors that may matter: exact botanical preparation; other medicines; baseline drowsiness.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed clozapine.
Clozapine can cause sedation and impaired cognitive or motor performance; somnolence and instability can contribute to falls. Severe hepatotoxicity has been reported.
How this applies: Medication-specific safety context only; no direct botanical interaction or automatic dose change is established.
Does not name any of the six botanical counterparties or quantify their combined risks.
Source 2: federal botanical safety guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: Users of valerian preparations.
Possible but unproven sleep-inducing effects; advises against use with alcohol or sedatives. Mental dullness is a reported side effect.
How this applies: Botanical-only evidence; relevance to clozapine requires separate interpretation.
General advice does not measure a clozapine interaction, a dose-response relationship or a safe spacing interval.
Research assessment: · Open full citations ↗
Side effects & toxicity
A four-week valerian trial did not improve insomnia more than placebo; this does not settle sedation risk with clozapine.
- Exact scope
- Valeriana officinalis root and rhizome preparations taken by mouth; blends and other valerian species are not equivalent. with Oral clozapine, RxNorm 2626 IN.
- Medication form and route
- oral clozapine; oral botanical preparation
What remains uncertain
- Efficacy endpoint and different population; no pair-specific interaction assessment.
Factors that may matter: exact botanical preparation; other medicines; baseline drowsiness.
Read the supporting source summaries
Source 1: randomized human trial
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 391 people with anxiety and insomnia.
Neither kava nor valerian improved its primary symptom outcome more than placebo.
How this applies: Botanical-only evidence; relevance to clozapine requires separate interpretation.
No clozapine exposure comparison; efficacy null is not evidence that sedation or interactions cannot occur.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Preparation-specific evidence and uncertainty assessed. | |
| Research summary published |
Article revision: e8f37e9f30c64310
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.