Is Garlic Extract Safe with Warfarin?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid high-dose garlic supplements while on warfarin. If dietary garlic intake changes significantly, inform your doctor. Monitor for signs of bleeding such as unusual bruising or prolonged cuts. Schedule more frequent INR checks.
Why this interaction occurs
Garlic extract, particularly allicin and ajoene compounds, inhibits platelet aggregation and may weakly inhibit CYP2C9, the primary enzyme responsible for warfarin metabolism. This can elevate warfarin levels and enhance its anticoagulant effect, increasing hemorrhagic risk.
Evidence
Evidence level: moderate.
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 Garlic Extract interactions → · All Warfarin interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.