Moderate interactionModerate
Leafy greens and Warfarin: interaction, severity and spacing
Leafy greens and Warfarin interact because vitamin K1 from leafy greens competes with warfarin. The risk is variability more than the amount: a sudden jump in intake lowers the INR. Take them with care. Moderate risk.
Last reviewed: 2026-09-20Reviewed by: StackingRight clinical review
The interaction in detail
| Pair | Leafy greens and Warfarin |
|---|---|
| Type | Food interaction |
| Severity | Moderate |
| Required spacing | None specified |
| Onset | At the time of dosing |
Mechanism
Vitamin K1 from leafy greens competes with warfarin. The risk is variability more than the amount: a sudden jump in intake lowers the INR.
What to do
Keep your leafy-green intake consistent week to week rather than avoiding greens entirely.
How to fit both into one day
Warfarin
eveningflexible
An evening dose is conventional so the INR drawn the next morning reflects a stable interval. Keep vitamin K intake consistent.
Putting Leafy greens in the morning and Warfarin in the evening satisfies the 0-hour separation without disrupting either one's absorption window.