The short answer
Review ashwagandha with your prescriber before taking it with phenobarbital. Some preparations cause drowsiness, and official guidance flags possible interactions with sedatives and antiseizure medicines.
What this answer covers
Oral Withania somnifera; the cited sleep trial used a specific root extract, not all leaf/root preparations.
- Supplement or preparation
- Withania somnifera
- Medication ingredient
- phenobarbital
Why a review is sensible
Ashwagandha can cause drowsiness in some people. NCCIH identifies possible interactions with sedatives and anticonvulsants, while phenobarbital itself can impair alertness.
A sleep trial does not answer this combination question
A specific root-extract trial reported no adverse events, but excluded regular medication users. That finding cannot establish safety in someone taking phenobarbital.
Check the product rather than inventing a gap
Bring its species, plant part, extract and full ingredient list. There is no validated number of hours between doses that makes the combination safe.
Watch for impaired alertness
Phenobarbital can cause drowsiness and impaired coordination. Avoid driving when affected, and seek urgent help for severe difficulty waking or breathing. Other sedating medicines and alcohol make a careful medication review especially important.
Evidence and practical considerations
Timing & monitoring
Conditional avoidance/review of an added sedating botanical is supported; no established exact-pair risk rate or timing solution.
- Exact scope
- Oral Withania somnifera; the cited sleep trial used a specific root extract, not all leaf/root preparations. with Exact oral phenobarbital; parent and metabolites distinguished; no other drug/route assumed equivalent.
- Medication form and route
- oral supplement unless pregnancy section explicitly distinguishes neonatal injection
- Timing or duration
- Preparation, dose and duration determine applicability; chronic nutrition evidence is not a single-dose interaction.
What remains uncertain
- Trial excluded regular medication users; no phenobarbital co-use safety evidence. Root extract results do not establish leaf or mixture equivalence.
Factors that may matter: exact supplement identity; dose; other medicines; clinical indication; baseline nutrition; pregnancy where relevant.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed oral phenobarbital.
Causes CNS depression and can impair driving; other CNS depressants can add to these effects. Adult plasma half-life is prolonged. Abrupt withdrawal after dependence can cause seizures and other serious symptoms. Long-term treatment warrants periodic clinical and laboratory assessment.
How this applies: Exact RxCUI 8134 IN and UNII YQE403BP4D, oral plain ingredient; no automatic sodium-injection or other barbiturate transfer.
Does not name the requested botanicals or establish supplement-specific interaction rates or spacing. Current DailyMed listing is unapproved drug other, not evidence of FDA approval.
Source 2: official guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: People considering the specified supplement.
Some preparations cause drowsiness; possible interactions with sedatives and anticonvulsants. Long-term safety is uncertain.
How this applies: Preparation-specific context; not a directly measured either requested antiseizure drug interaction.
No direct either requested antiseizure drug study; short-term safety observations do not establish long-term safety.
Source 3: randomized placebo-controlled trial
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 60 adults enrolled with insomnia and anxiety.
Some sleep outcomes improved; no adverse events were reported. Morning alertness did not differ significantly between groups at ten weeks.
How this applies: Preparation-specific context; not a directly measured either requested antiseizure drug interaction.
Regular medication users and people with restless legs syndrome or other sleep disorders were excluded. Exploratory study; internal reporting inconsistencies in analysis counts. Cannot extend to either requested antiseizure drug-treated patients or leaf preparations.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Exact current available claims reviewed against captured originals; no clinical review asserted. | |
| Research summary published |
Article revision: e5e5d96cfe8e48d5
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.