Database Methodology & Disclaimer
How we compile, grade, and present herb-drug interaction data — and its limitations.
Medical Disclaimer
The herb-drug interaction information provided by HerbOS is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. This database is not a substitute for professional medical consultation.
Always consult a qualified healthcare provider — including your prescribing physician and pharmacist — before combining herbal supplements with prescription medications or making changes to your medication regimen.
Professional tier content is intended exclusively for licensed healthcare professionals. Clinical management guidance represents synthesized, literature-based recommendations and does not replace individualized clinical judgment. Healthcare professionals should verify all information against current peer-reviewed literature before applying it to patient care.
Data Sources
Our interaction database draws from the following primary sources:
- PubMed/MEDLINE — Primary peer-reviewed literature including pharmacokinetic studies, clinical trials, and case reports
- Natural Medicines Comprehensive Database — Evidence-graded natural product monographs
- WHO Monographs on Selected Medicinal Plants
- European Medicines Agency (EMA) Herbal Monographs
- American Herbal Pharmacopoeia (AHP) — Quality, purity, and identity standards
- Drug interaction databases (Lexicomp, Micromedex, DrugBank) — For cross-referencing pharmacokinetic data
- Pharmacovigilance reports — FDA MedWatch, EudraVigilance, and WHO-UMC VigiBase for spontaneous adverse event reports
How Evidence Levels Are Determined
Each interaction is assigned an evidence level reflecting the strength and type of available evidence, from strongest to weakest:
Systematic pooling of data from multiple clinical trials. Highest level of evidence.
Comprehensive synthesis of existing research using defined methodology.
Controlled human studies — pharmacokinetic studies or randomized trials.
Cohort or cross-sectional studies in humans, without randomization.
Published individual case reports or series documenting the interaction.
Evidence from animal models only; extrapolation to humans is uncertain.
Laboratory studies only; clinical relevance at physiological concentrations is uncertain.
Clinical Significance Ratings
Separate from evidence level, we assign a clinical significance rating:
- Established — Well-documented in multiple high-quality human studies; clinically confirmed
- Probable — Consistent evidence from multiple sources; clinical occurrence is expected
- Possible — Limited or conflicting evidence; plausible mechanism exists
- Theoretical — Based on pharmacological reasoning or in vitro data only; not confirmed clinically
Database Limitations
Users of this database should be aware of the following inherent limitations:
- Preparation variability: The phytochemical composition of herbal products varies significantly between manufacturers, extraction methods, and plant parts used. Interaction severity may differ from published data if different preparations are used.
- Dose-dependence: Many interactions are dose-dependent. Culinary use of herbs (e.g., turmeric in cooking) differs substantially from high-dose supplementation.
- Individual variation: CYP450 enzyme polymorphisms, age, hepatic/ renal function, and concurrent medications affect interaction likelihood.
- Publication bias: Adverse event case reports are more likely to be published than null results; this may overrepresent certain interactions.
- Currency: The published literature evolves continuously; our database undergoes periodic review but may not reflect the most recent publications.
- Completeness: The absence of an interaction in this database does not confirm safety. Many combinations have never been studied.
When to Seek Professional Help
Always seek urgent medical advice if you experience:
- Unusual or unexplained bleeding
- Signs of serotonin syndrome (agitation, tremor, high temperature, rapid heart rate)
- Severe sedation or confusion
- Sudden changes in blood pressure
- Symptoms of organ rejection (fever, graft site pain, declining function tests)
For questions about your specific medications and supplements, consult your pharmacist — they have access to your complete medication list and specialized drug interaction expertise.
Report Inaccurate Data
If you believe any interaction data in our database is inaccurate, incomplete, or outdated, please contact our clinical review team. We take data quality seriously and review all submissions.
clinical@herbos.appPlease include: the herb name, drug name, the specific field in question, and the supporting reference (PMID if available).