The short answer
Passionflower can cause drowsiness, so additional impairment with valproate is possible. Human evidence does not measure the risk for this combination, and some passionflower trials found no increased sedation.
What this answer covers
Oral Passiflora incarnata herb preparations; do not extend to other species, passion fruit or every combination product.
- Supplement or preparation
- Passiflora incarnata
- Medication ingredient
- valproate
The basis for caution
The valproate label warns about added nervous-system impairment with sedating substances. NCCIH lists drowsiness, dizziness and confusion as possible passionflower effects. That makes additional impairment plausible, but does not demonstrate a valproate-specific interaction.
Evidence is not uniformly sedating
In a trial of 60 surgical patients, a single passionflower product reduced anxiety without a detected increase in sedation scores. This was an acute study and did not test long-term valproate use. It limits a blanket claim that every passionflower exposure necessarily causes extra sedation.
Preparations and reported interactions
The European monograph covers particular Passiflora incarnata herb preparations and warns that driving may be impaired. It reports no interactions. That means none were reported in the monograph, not that combinations were proven safe. Different extracts and blends should be assessed separately.
What to discuss
Show the actual product to the treating team before use, especially if you already feel sleepy on valproate or take other sleep medicines. Report new impairment and avoid driving while affected. There is no established spacing rule that makes this combination safe.
Evidence and practical considerations
Side effects & toxicity
Possible additive sedation is an indirect precaution; null sedation scores in a non-valproate acute trial and absence of direct pair data prevent a stronger claim.
- Exact scope
- Oral Passiflora incarnata herb preparations; do not extend to other species, passion fruit or every combination product. with Oral valproate active moiety (RxNorm 40254 IN), with formulation boundaries preserved.
- Medication form and route
- oral valproate; oral supplement
What remains uncertain
- Evidence does not quantify all-product interaction risk; source-specific limits apply.
Factors that may matter: Indication; Exact preparation; Other sedating medicines.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed oral valproic acid; valproate somnolence trial in elderly dementia patients.
Valproate may impair alertness, especially with other CNS depressants. Older adults may have more somnolence. Major metabolic pathways are glucuronidation and beta-oxidation; CYP oxidation is relatively minor. Serious liver injury is an intrinsic risk.
How this applies: Explicit oral active-moiety bridge to RxNorm IN 40254 valproate; no dose conversion or intravenous extrapolation.
No named interaction with the seven supplements. Active-moiety relevance does not establish identical kinetics or dosing for every valproate formulation.
Source 2: federal supplement safety guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: Users of the specified supplement.
Possible adverse effects include drowsiness, dizziness and confusion; excessive nervous-system slowing is a concern with anesthesia and perioperative medicines.
How this applies: Supplement-only guidance interpreted alongside the medication label.
Does not quantify a valproate interaction or establish protective dose spacing.
Source 3: original human randomized study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 60 adults undergoing ambulatory surgery.
Anxiety decreased without a detected difference in sedation scores or recovery measures.
How this applies: Applies only to the stated preparation, population and measured endpoints.
Not chronic valproate co-use; no inference that every extract is nonsedating.
Source 4: final regulatory herbal monograph
ema.europa.eu · Source check Sep 10, 2026
Population: Users of specified oral passionflower preparations.
Traditional use for mild stress and sleep; no interactions reported; may impair driving and machinery use.
How this applies: Applies to specified Passiflora incarnata herb preparations, not all passionflower species or blends.
Traditional-use monograph reports no interactions, but this is not evidence of a tested safe combination with valproate.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Prepared article with direct-study limits, preparation boundaries and claim-specific conclusions. | |
| Research summary published |
Article revision: 33de0244d3758dbd
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.