The short answer
St John’s wort has not been shown here to reduce asenapine absorption or cause a specific adverse interaction. Review the herb, but keep sublingual and patch instructions separate.
What this answer covers
Oral Hypericum perforatum with sublingual asenapine maleate or transdermal asenapine, distinguished explicitly.
- Supplement or preparation
- Hypericum perforatum
- Medication ingredient
- asenapine
The exact label limits a broad CYP claim
SAPHRIS labeling says no dose adjustment is needed with CYP3A4 inducers such as carbamazepine based on pharmacokinetic studies. It does not name St John’s wort as a tested product.
Metabolism is not solely CYP3A4
Asenapine uses UGT1A4 and CYP1A2, with smaller CYP3A4 and CYP2D6 contributions. An interaction with a different CYP3A4-sensitive medicine does not establish one with asenapine.
Keep the administration rules separate
After a sublingual SAPHRIS dose, do not eat or drink for ten minutes. That is an absorption instruction for the tablet, not proof of a St John’s wort interaction or a spacing rule for the patch.
Bring the actual extract for review
St John’s wort preparations differ, and probe studies include both induction and minimal-effect findings. Discuss the full mood regimen before adding it or changing asenapine.
Evidence and practical considerations
Side effects & toxicity
Exact reduced-effectiveness and toxicity claims remain insufficient; current label contains contrary CYP3A4-inducer guidance.
- Exact scope
- Oral Hypericum perforatum with sublingual asenapine maleate or transdermal asenapine, distinguished explicitly. with Exact asenapine maleate sublingual tablets or asenapine transdermal system, distinguished by route. Exact RxNorm IN784649; SAPHRIS maleate sublingual tablet and SECUADO asenapine transdermal system distinguished. Do not assign swallowed-tablet or sublingual food/drink instructions to the patch.
- Medication form and route
- sublingual; transdermal
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- No exact herb co-use study; other CYP probe effects cannot override asenapine’s own clinical labeling.
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 asenapine.
Somnolence, orthostatic and QT precautions. UGT1A4 and CYP1A2 major metabolism; no dose adjustment advised with CYP3A4 inducers based on PK studies. Do not eat or drink for ten minutes after a sublingual dose.
How this applies: Exact asenapine maleate sublingual route; patch instructions require the separate SECUADO label.
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 asenapine co-use is not inferred from another medicine or route.
General herb-drug precaution, not an exact asenapine exposure or adverse-event result.
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: official product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: Adults with schizophrenia prescribed asenapine patches.
Somnolence, cognitive/motor, orthostatic and QT precautions; clinical interaction data include studies of sublingual asenapine.
How this applies: Exact ingredient in a distinct transdermal formulation; route bridge kept explicit.
No exact supplement interaction study; sublingual food/drink interval cannot be assigned to the patch.
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: 50074c2e65a8d541
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.