The short answer
Review ginkgo before use with thioridazine, particularly with a seizure history. Ginkgo guidance raises a precaution in epilepsy, but the original reports do not establish a thioridazine-specific seizure rate.
What this answer covers
Oral thioridazine with the exact supplement preparation described.
- Supplement or preparation
- Ginkgo biloba
- Medication ingredient
- thioridazine
The precaution is strongest when seizures are already a concern
The ginkgo leaf monograph says additional seizures cannot be excluded in people with epilepsy. Thioridazine labeling also describes rare seizures and the need to maintain appropriate anticonvulsant treatment.
The case reports are signals with limits
Two reported patients with controlled epilepsy had recurrent seizures after starting ginkgo. A separate fatal case involved multiple supplements and low anticonvulsant levels. The inspected reports do not identify thioridazine as the tested combination.
Do not merge seeds, extracts and other medicines
The monograph concerns specified leaf preparations. Seed poisoning and interactions with anticonvulsants involve different exposures and cannot be used to assign every leaf product a thioridazine-specific risk percentage.
Keep seizure care and medicine changes coordinated
Discuss the product before use, especially with epilepsy or other threshold-lowering medicines. Do not alter prescribed anticonvulsants or thioridazine yourself. No supplement dosing gap was established to prevent this possible problem.
Evidence and practical considerations
Side effects & toxicity
Review ginkgo before use with thioridazine, particularly with a seizure history. Ginkgo guidance raises a precaution in epilepsy, but the original reports do not establish a thioridazine-specific seizure rate.
- Exact scope
- Oral thioridazine with the exact supplement preparation described. with Oral thioridazine with the stated label and formulation limits.
- Medication form and route
- oral
What remains uncertain
- Conditional seizure-history precaution from the medicine label and leaf monograph. Cases do not identify thioridazine and include low anticonvulsant levels or multiple supplements. No exact-pair incidence, seed-to-leaf equivalence or protective interval is established.
Factors that may matter: Exact preparation and amount; Other medicines; Seizure history, alertness or electrolyte status where relevant.
Read the supporting source summaries
Source 1: Current U.S. regulatory product labeling
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Patients prescribed oral thioridazine.
CYP2D6 inhibition or reduced activity can increase thioridazine exposure and potentially fatal QT-related arrhythmias. Baseline ECG and potassium testing, potassium correction before treatment and periodic monitoring are recommended. Drowsiness and rare seizures are described.
How this applies: Exact ingredient and oral-route clinical context.
Label class warnings do not establish every exact botanical interaction, event rate or protective supplement interval.
Source 2: Original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Two people with previously controlled epilepsy.
Seizures recurred after initiation and did not recur during reported follow-up after discontinuation.
How this applies: Raises a seizure-history precaution without proving the exact combination.
Case reports, no thioridazine identified in the inspected abstract, no incidence estimate or controlled causality.
Source 3: Original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: One man with epilepsy who died after a breakthrough seizure.
The authors discussed a possible supplement contribution, but multiple exposures and low anticonvulsant levels complicated attribution.
How this applies: Confounded serious case must not become an exact-pair causal claim.
No exact thioridazine co-use identified; the proposed enzyme mechanism was not a controlled pharmacokinetic demonstration.
Source 4: Regulatory herbal monograph
ema.europa.eu · Source check Sep 10, 2026
Population: People considering covered ginkgo leaf preparations.
States that further seizures promoted by ginkgo preparations cannot be excluded in people with epilepsy.
How this applies: Supports individualized review of seizure history.
Precautionary wording does not quantify a thioridazine combination or equate seed poisoning with leaf extracts.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Initial source-checked draft with exact preparation limits, original study findings and uncertainty. Clinical review not recorded. | |
| Research summary published |
Article revision: a501afb1d5542c3c
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.