Is Iodine Safe with Warfarin?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Monitor INR more frequently if iodine supplement use changes thyroid status. Report any unusual bleeding or bruising. Maintain consistent iodine intake and inform your anticoagulation clinic of all supplement use.
Why this interaction occurs
Thyroid hormones influence vitamin K-dependent clotting factor synthesis and warfarin metabolism. Iodine-induced changes in thyroid function (hypo- or hyperthyroid shifts) can alter warfarin sensitivity and INR stability, increasing bleeding or clotting 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 Iodine interactions → · All Warfarin interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.