The short answer
An exact St John’s wort effect on iloperidone absorption, effectiveness or side effects is not established. Review the herb and all other medicines with the prescriber.
What this answer covers
Oral Hypericum perforatum with iloperidone tablets.
- Supplement or preparation
- Hypericum perforatum
- Medication ingredient
- iloperidone
Known metabolism interactions involve other products
Iloperidone labeling describes CYP2D6 and CYP3A4 inhibitor interactions. This does not establish the amount, direction or clinical outcome of a St John’s wort interaction.
The cardiac study did not use this herb
Iloperidone QT effects increased with paroxetine and ketoconazole. Those inhibitor results are not evidence that St John’s wort causes the same effect.
Extract-specific results matter
St John’s wort changed an alprazolam probe in one study, while low-hyperforin evidence showed little effect. These findings cannot define an iloperidone dose adjustment or a safe herb product.
Review before changing either product
Bring the extract and all medicines to the prescriber. Do not increase iloperidone to offset assumed reduced absorption or rely on an untested time gap.
Evidence and practical considerations
Side effects & toxicity
Exact reduced-effectiveness and toxicity claims remain insufficient; no herb-specific outcome or validated spacing identified.
- Exact scope
- Oral Hypericum perforatum with iloperidone tablets. with Exact iloperidone oral tablets. Exact RxNorm IN73178; oral iloperidone tablets. CYP2D6/CYP3A4 and QT precautions, not automatic electrolyte supplementation.
- Medication form and route
- oral
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- Inhibitor studies cannot be reversed into a quantified inducer effect; preparation-specific probe findings do not establish this pair.
Factors that may matter: preparation and plant part; clinical indication; dose; other medicines; baseline alertness.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed iloperidone.
Orthostatic hypotension, sedation, QT prolongation and baseline/periodic potassium-magnesium monitoring in at-risk patients; CYP2D6/CYP3A4 inhibitor sensitivity.
How this applies: Exact RxNorm IN73178; oral iloperidone tablets. CYP2D6/CYP3A4 and QT precautions, not automatic electrolyte supplementation.
No supplement-specific event rate, universal timing rule or untested route/preparation equivalence.
Source 2: official botanical guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: Users of Hypericum perforatum.
Certain antidepressant combinations may cause serious serotonin-related side effects; herb can reduce the effects of some medicines.
How this applies: Preparation-specific evidence; exact iloperidone co-use is not inferred from another medicine or route.
General herb-drug interaction precaution, not an iloperidone co-use trial.
Source 3: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Twelve healthy volunteers in an open-label fixed-order crossover.
Alprazolam exposure fell about one-half and clearance increased; elimination half-life shortened.
How this applies: Preparation-specific original evidence; no untested antidepressant or route transfer.
Single extract and short exposure, healthy volunteers; no anxiety-treatment failure endpoint. Does not imply reduced gut absorption or transfer to predominantly conjugated benzodiazepines.
Source 4: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Healthy participants in randomized placebo-controlled studies.
Changes in probe exposures were small and judged clinically irrelevant; hyperforin levels were below quantification.
How this applies: Preparation-specific original evidence; no untested antidepressant or route transfer.
Preparation-specific result, not permission to assume all retail products are low-hyperforin or all doses safe.
Source 5: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: 188 adults with schizophrenia or schizoaffective disorder and normal baseline ECGs randomized among treatments.
QTc increased with iloperidone and more with metabolic inhibition; no QTc at or above 500 ms in the study.
How this applies: Only the named drug, preparation, route and measured endpoints apply.
No St John’s wort, magnesium or potassium supplementation experiment. QT changes are not an exact supplement arrhythmia rate.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Research summary published | |
| Article prepared | |
| Current exact available claims adjudicated using original captures and explicit identity and comparator limits. |
Article revision: e7d018f611f6f801
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.