The short answer
St John’s wort warrants a serotonin-risk review before use with tapentadol. A specific increase in seizures from this combination has not been established, and a short spacing interval is not a proven safeguard.
What this answer covers
Oral Hypericum perforatum preparations; product composition varies, and tapentadol is not primarily CYP-cleared.
- Supplement or preparation
- Hypericum perforatum
- Medication ingredient
- tapentadol
The serotonin concern is plausible
Tapentadol’s label warns about serotonergic combinations, and St John’s wort guidance warns of serious serotonin-related effects with other active drugs. This supports a precaution, not a measured exact-pair incidence.
Clinical reports and uncertainty both matter
A postoperative case developed serotonin toxicity after tapentadol was added to antidepressants. An earlier manufacturer safety analysis found many reports inadequately documented and did not confirm definite causation. Neither provides a supplement-specific risk rate.
Seizures and metabolism are separate questions
Tapentadol carries a seizure warning, especially in susceptible settings. This does not prove St John’s wort specifically adds seizure risk. The herb’s familiar CYP interactions also should not be assumed to control this mainly glucuronidated drug.
Review co-use and recognize warning signs
Discuss serotonin-active supplements before adding them. New agitation or confusion with fever, sweating, tremor or muscle stiffness needs urgent assessment. Do not change tapentadol yourself or assume that a short gap prevents toxicity.
Evidence and practical considerations
Timing & monitoring
Review and avoid unsupervised serotonergic co-use; not a universal prohibition or evidence for a short spacing interval.
- Exact scope
- Oral Hypericum perforatum preparations; product composition varies, and tapentadol is not primarily CYP-cleared. with Tapentadol RxCUI787390 IN supplied as HCl oral immediate-release or extended-release tablets.
- Medication form and route
- oral medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed tapentadol
Opioid and noradrenergic analgesic actions; warnings for CNS-depressant combinations, serotonin syndrome with serotonergic drugs, and seizures in susceptible settings. Mainly glucuronidated; limited CYP metabolism.
How this applies: Exact tapentadol RxCUI 787390 IN, with stated salt/formulation/route bridge.
No herbal-pair risk rate. Immediate and extended release differ. General seizure warning does not establish a St John’s wort-specific seizure interaction.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed tapentadol
Opioid and noradrenergic analgesic actions; warnings for CNS-depressant combinations, serotonin syndrome with serotonergic drugs, and seizures in susceptible settings. Mainly glucuronidated; limited CYP metabolism.
How this applies: Exact tapentadol RxCUI 787390 IN, with stated salt/formulation/route bridge.
No herbal-pair risk rate. Immediate and extended release differ. General seizure warning does not establish a St John’s wort-specific seizure interaction.
Source 3: federal supplement safety guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: Users of the named oral supplement
Possible serious serotonin-related effects with other serotonin-active drugs.
How this applies: Interpreted with current exact tapentadol label.
General guidance, not a direct tapentadol pair trial or measured incidence.
Source 4: original transporter experiment
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Human-transporter cell models, plus separate report review.
Tapentadol inhibited NET most strongly among tested opioids and also inhibited SERT in human-transporter cells at potentially relevant concentrations.
How this applies: Original source interpreted for tapentadol only within the stated preparation and endpoint limits.
Cell experiments and case-report associations do not quantify clinical tapentadol-supplement risk.
Source 5: original case report
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: One postoperative patient.
Hyperthermia, inducible clonus, hyperreflexia and altered mental state developed; improvement after stopping serotonergic medicines.
How this applies: Multiple drugs and infection confound attribution; not an herbal or supplement pair.
Multiple drugs and infection confound attribution; not an herbal or supplement pair.
Source 6: original integrated safety-data analysis
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Clinical-study and postmarketing tapentadol populations.
Most reported serotonin cases lacked robust diagnostic data; no cases in the interventional database, and the analysis did not confirm a definite causal association.
How this applies: Sponsor-funded descriptive analysis, underreporting and incomplete data; absence of confirmation is not absence of risk or an exact supplement safety result.
Sponsor-funded descriptive analysis, underreporting and incomplete data; absence of confirmation is not absence of risk or an exact supplement safety result.
Research assessment: · Open full citations ↗
Side effects & toxicity
Compound serotonin-syndrome/seizure claim is insufficient as written: conditional serotonin precaution is reasonable, but exact-pair added seizure risk not established.
- Exact scope
- Oral Hypericum perforatum preparations; product composition varies, and tapentadol is not primarily CYP-cleared. with Tapentadol RxCUI787390 IN supplied as HCl oral immediate-release or extended-release tablets.
- Medication form and route
- oral medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed tapentadol
Opioid and noradrenergic analgesic actions; warnings for CNS-depressant combinations, serotonin syndrome with serotonergic drugs, and seizures in susceptible settings. Mainly glucuronidated; limited CYP metabolism.
How this applies: Exact tapentadol RxCUI 787390 IN, with stated salt/formulation/route bridge.
No herbal-pair risk rate. Immediate and extended release differ. General seizure warning does not establish a St John’s wort-specific seizure interaction.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed tapentadol
Opioid and noradrenergic analgesic actions; warnings for CNS-depressant combinations, serotonin syndrome with serotonergic drugs, and seizures in susceptible settings. Mainly glucuronidated; limited CYP metabolism.
How this applies: Exact tapentadol RxCUI 787390 IN, with stated salt/formulation/route bridge.
No herbal-pair risk rate. Immediate and extended release differ. General seizure warning does not establish a St John’s wort-specific seizure interaction.
Source 3: federal supplement safety guidance
nccih.nih.gov · Source check Sep 10, 2026
Population: Users of the named oral supplement
Possible serious serotonin-related effects with other serotonin-active drugs.
How this applies: Interpreted with current exact tapentadol label.
General guidance, not a direct tapentadol pair trial or measured incidence.
Source 4: original transporter experiment
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Human-transporter cell models, plus separate report review.
Tapentadol inhibited NET most strongly among tested opioids and also inhibited SERT in human-transporter cells at potentially relevant concentrations.
How this applies: Original source interpreted for tapentadol only within the stated preparation and endpoint limits.
Cell experiments and case-report associations do not quantify clinical tapentadol-supplement risk.
Source 5: original case report
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: One postoperative patient.
Hyperthermia, inducible clonus, hyperreflexia and altered mental state developed; improvement after stopping serotonergic medicines.
How this applies: Multiple drugs and infection confound attribution; not an herbal or supplement pair.
Multiple drugs and infection confound attribution; not an herbal or supplement pair.
Source 6: original integrated safety-data analysis
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Clinical-study and postmarketing tapentadol populations.
Most reported serotonin cases lacked robust diagnostic data; no cases in the interventional database, and the analysis did not confirm a definite causal association.
How this applies: Sponsor-funded descriptive analysis, underreporting and incomplete data; absence of confirmation is not absence of risk or an exact supplement safety result.
Sponsor-funded descriptive analysis, underreporting and incomplete data; absence of confirmation is not absence of risk or an exact supplement safety result.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Prepared exact tapentadol article with formulation-specific evidence and uncertainty. | |
| Research summary published |
Article revision: 5312629dc6c8d5f6
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?
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Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.