The short answer
Fluoxetine specifically warns about St John’s wort and serotonin syndrome. Avoid starting the herb without prescriber review; evidence does not establish a simple spacing rule or reduced fluoxetine absorption.
What this answer covers
Oral Hypericum perforatum with fluoxetine capsules; exact herb formulation and other serotonergic medicines matter.
- Supplement or preparation
- Hypericum perforatum
- Medication ingredient
- fluoxetine
The label names this herb
Fluoxetine includes St John’s wort among serotonergic agents of concern. Review both supplements and migraine medicines with the prescriber.
A reported case had several contributors
Seizure and rhabdomyolysis were reported with fluoxetine, Hypericum and eletriptan. The authors attributed the episode to the drug combination.
The diagnosis was challenged
Subsequent clinical correspondence questioned whether serotonin-toxicity criteria were met and whether alternative causes were excluded. The case therefore cannot provide a certain pair-specific diagnosis or risk estimate.
Spacing does not solve the evidence gap
Fluoxetine and its active metabolite persist for a long time. There is no validated supplement gap, and the case does not show reduced absorption. Seek urgent assessment for a cluster of confusion, fever and abnormal muscle activity.
Evidence and practical considerations
Side effects & toxicity
Conditional exact-label serotonergic precaution. The reported multidrug case is diagnostically disputed; reduced fluoxetine effectiveness or absorption remains insufficient.
- Exact scope
- Oral Hypericum perforatum with fluoxetine capsules; exact herb formulation and other serotonergic medicines matter. with Exact oral fluoxetine hydrochloride capsules. RxNorm IN 4493/PIN 227224 hydrochloride capsules. Active norfluoxetine and prolonged elimination matter. Not the combined olanzapine product.
- Medication form and route
- oral
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- Case also involved eletriptan and lacked definitive attribution; no fluoxetine-Hypericum PK study identified.
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 oral fluoxetine.
Exact label names tryptophan and St John’s wort in serotonin warnings, warns about bleeding and mania, and describes long elimination of fluoxetine and norfluoxetine.
How this applies: RxNorm IN 4493/PIN 227224 hydrochloride capsules. Active norfluoxetine and prolonged elimination matter. Not the combined olanzapine product.
No universal supplement interval, event rate or preparation equivalence established. Original label distinguishes warnings from measured pair-specific results.
Source 2: original case report
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: One woman taking fluoxetine, self-prescribed Hypericum and eletriptan.
Seizure and rhabdomyolysis followed; authors attributed the episode to the combination.
How this applies: Only the named drug, preparation, route and measured endpoints apply.
Three-drug exposure, uncertain herb formulation and subsequently disputed diagnostic criteria. Not an uncontested exact-pair serotonin-syndrome proof or incidence estimate.
Source 3: original clinical correspondence
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Critical reappraisal of the fluoxetine-Hypericum-eletriptan case.
Author argued that Hunter criteria were not met and alternative causes were insufficiently excluded.
How this applies: Only the named drug, preparation, route and measured endpoints apply.
Critique does not establish safety or identify a proven alternative cause; it limits certainty of the original diagnosis.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Current exact available claims adjudicated using original captures and explicit identity and comparator limits. | |
| Research summary published |
Article revision: 21f2ed239dc839d3
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.