St. John's Wort and Warfarin: Can You Take Them Together?
Here's what FDA drug labeling and NIH supplement data show.
Interaction Found
What happens: St. John's Wort induces CYP enzymes that metabolize warfarin faster, reducing its anticoagulant effect.
What to do: Avoid combination. INR monitoring required if used together.
Source: FDA-approved drug labeling and NIH Office of Dietary Supplements fact sheets.
Learn more
Warfarin — full safety profile, side effects, and all known interactions.
St. John's Wort — supplement labels containing this ingredient.
Frequently asked questions
Can I take St. John's Wort with Warfarin?
Avoid combination. INR monitoring required if used together.
What happens if you take St. John's Wort and Warfarin together?
St. John's Wort induces CYP enzymes that metabolize warfarin faster, reducing its anticoagulant effect.
What should I do if I take both?
Avoid combination. INR monitoring required if used together. Always consult your healthcare provider before combining supplements and medications.
SafeCheck provides drug interaction information from FDA-approved product labeling (openFDA). This is for informational purposes only and is not medical advice. Always consult your healthcare provider before making medication decisions.