Severe interactionSevere
St. John's Wort and Direct anticoagulant: interaction, severity and spacing
St. John's Wort and Direct anticoagulant interact because st. John's Wort induces P-glycoprotein and CYP3A4, lowering blood levels of direct oral anticoagulants and risking therapeutic failure. Take them with care. Severe risk.
Last reviewed: 2026-09-20Reviewed by: StackingRight clinical review
The interaction in detail
| Pair | St. John's Wort and Direct anticoagulant |
|---|---|
| Type | Nutrient–drug interaction |
| Severity | Severe |
| Required spacing | None specified |
| Onset | At the time of dosing |
Mechanism
St. John's Wort induces P-glycoprotein and CYP3A4, lowering blood levels of direct oral anticoagulants and risking therapeutic failure.
What to do
Avoid the combination entirely and tell your prescriber if you have started it.
How to fit both into one day
St. John's Wort
morningwith food
Take with food to reduce GI upset. It is a potent enzyme inducer with a long list of interactions — treat it as a medication, not a herb.
Putting St. John's Wort in the morning and Direct anticoagulant in the evening satisfies the 0-hour separation without disrupting either one's absorption window.