MODERATE — Monitor Closely
CAUTION — consistent moderate intake is key; avoid large fluctuations or high-dose supplements
Evidence level: MODERATE
High-dose garlic supplements may increase bleeding risk with warfarin by adding antiplatelet effects.
High-dose garlic has antiplatelet activity (inhibits platelet aggregation via ajoene and allicin). May increase INR and bleeding risk with warfarin.
Avoid high-dose garlic supplements while on warfarin. Consistent dietary garlic intake is lower risk. Inform anticoagulation clinic.
Use caution. Many botanicals affect blood clotting — ginkgo, garlic, ginger, turmeric, and dong quai all have antiplatelet activity that can amplify Warfarin. St. John's Wort can REDUCE anticoagulant effectiveness. Take at separate times and inform your prescriber about all herbal supplements. Request more frequent INR monitoring if on warfarin.
High-dose garlic supplements (vs culinary amounts), concurrent other antiplatelet agents
Increased bruising, bleeding, elevated INR
Tell anticoagulation clinic about garlic supplement use. Culinary garlic is generally fine if consistent.
Blood thinners have narrow safety margins. Instead of Garlic Extract, consider safer options: CoQ10 (with INR monitoring), vitamin D3, or probiotics — these have minimal anticoagulant interactions. Always inform your anticoagulation clinic about any supplements.
High-dose garlic supplements may increase bleeding risk with warfarin by adding antiplatelet effects.
Use caution. Many botanicals affect blood clotting — ginkgo, garlic, ginger, turmeric, and dong quai all have antiplatelet activity that can amplify Warfarin. St. John's Wort can REDUCE anticoagulant effectiveness. Take at separate times and inform your prescriber about all herbal supplements. Request more frequent INR monitoring if on warfarin.
Increased bruising, bleeding, elevated INR
Blood thinners have narrow safety margins. Instead of Garlic Extract, consider safer options: CoQ10 (with INR monitoring), vitamin D3, or probiotics — these have minimal anticoagulant interactions. Always inform your anticoagulation clinic about any supplements.
Tell anticoagulation clinic about garlic supplement use. Culinary garlic is generally fine if consistent.
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