The short answer
Nortriptyline explicitly warns about St John’s wort and serotonin syndrome. Discuss any use with the prescriber; separating doses has not been shown to prevent this risk.
What this answer covers
Oral Hypericum perforatum. An amitriptyline metabolite study is indirect for prescribed nortriptyline.
- Supplement or preparation
- Hypericum perforatum
- Medication ingredient
- nortriptyline
The label names this herb
Nortriptyline information specifically includes St John’s wort among serotonergic agents of concern. Review it before adding or stopping it.
The level study used a different prescription
Hypericum lowered amitriptyline and its nortriptyline metabolite levels in twelve patients. They were prescribed amitriptyline, so the result does not quantify what happens when nortriptyline itself is prescribed.
A timing gap is not established protection
The label provides no supplement-spacing rule. Do not increase nortriptyline based on the metabolite result or use a gap as assurance of safe co-use.
Recognize concerning symptoms
Seek urgent medical care for a combination of agitation or confusion, fever or heavy sweating, tremor, muscle rigidity or repeated twitching. These can be signs of serotonin syndrome; a single nonspecific symptom does not establish the diagnosis.
Evidence and practical considerations
Side effects & toxicity
Exact-label serotonin precaution supports conditional avoidance/review; reduced nortriptyline effectiveness or absorption is not established by a metabolite study.
- Exact scope
- Oral Hypericum perforatum. An amitriptyline metabolite study is indirect for prescribed nortriptyline. with Exact oral nortriptyline hydrochloride capsules. RxNorm IN 7531/PIN 203130 hydrochloride. A nortriptyline measurement during amitriptyline use represents a metabolite exposure, not directly prescribed nortriptyline.
- Medication form and route
- oral
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- Metabolite exposure during amitriptyline treatment cannot be converted into an exact nortriptyline dose adjustment or absorption claim.
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 nortriptyline.
Exact label names tryptophan and St John’s wort in serotonin-syndrome warnings; CYP2D6, cardiovascular and anticholinergic interactions require individual review.
How this applies: RxNorm IN 7531/PIN 203130 hydrochloride. A nortriptyline measurement during amitriptyline use represents a metabolite exposure, not directly prescribed nortriptyline.
No universal supplement interval, event rate or preparation equivalence established. Original label distinguishes warnings from measured pair-specific results.
Source 2: original human study
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Twelve patients prescribed amitriptyline.
Amitriptyline AUC fell 22 percent and nortriptyline metabolite AUC fell 41 percent.
How this applies: Only the named drug, preparation, route and measured endpoints apply.
Nortriptyline arose as an amitriptyline metabolite; this is not directly prescribed nortriptyline and does not measure reduced intestinal absorption specifically.
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: 0a8795df5f0ab242
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.