Is Grapefruit Juice Safe with warfarin?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Use grapefruit juice cautiously and consistently. Inform your doctor of your grapefruit juice consumption and monitor INR if intake changes.
Why this interaction occurs
Grapefruit juice can interact with warfarin through CYP450 pathways, potentially inhibiting warfarin metabolism and increasing warfarin exposure and INR.
Evidence
Evidence level: strong.
Data source
FDA Drug Label
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 134,328 reports mentioning warfarin. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the warfarin + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Grapefruit Juice interactions → · All warfarin interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.