Use of St. John's Wort in potentially dangerous combinations

J Altern Complement Med. 2014 Jul;20(7):578-9. doi: 10.1089/acm.2013.0216. Epub 2014 Jun 23.


Objectives: The objective of this study was to assess how often St. John's wort (SJW) is prescribed with medications that may interact dangerously with it.

Design: The study design was a retrospective analysis of nationally representative data from the National Ambulatory Medical Care Survey.

Settings: The study setting was U.S. nonfederal outpatient physician offices.

Subjects: Those prescribed SJW between 1993 and 2010 were the subjects.

Outcome measures: The outcome measures were medications co-prescribed with SJW.

Results: Twenty-eight percent (28%) of SJW visits involved a drug that has potentially dangerous interaction with SJW. These included selective serotonin reuptake inhibitors, benzodiazepines, warfarin, statins, verapamil, digoxin, and oral contraceptives.

Conclusions: SJW is frequently used in potentially dangerous combinations. Physicians should be aware of these common interactions and warn patients appropriately.

MeSH terms

  • Antidepressive Agents / therapeutic use
  • Herb-Drug Interactions*
  • Humans
  • Hypericum*
  • Phytotherapy / adverse effects*
  • Phytotherapy / methods*
  • Plant Extracts / administration & dosage*
  • Plant Extracts / adverse effects*
  • Prescriptions
  • Retrospective Studies
  • United States


  • Antidepressive Agents
  • Plant Extracts