Is Willow Bark Safe with Warfarin?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
This combination should be avoided. Willow bark's salicylate content can unpredictably elevate INR. Report any unusual bruising, bleeding gums, or blood in urine to your provider immediately.
Why this interaction occurs
Salicylates from willow bark can displace warfarin from plasma protein binding sites and inhibit platelet function, leading to dramatically elevated anticoagulation effect and life-threatening hemorrhage risk.
Evidence
Evidence level: moderate.
Data source
PubMed: PMID 25839871, PMID 17723077
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 Willow Bark interactions → · All Warfarin interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.