I take warfarin (Coumadin), an anticoagulant drug. Are there supplements I should avoid, or be taking, due to this drug?

Answer:

Yes, the effectiveness of warfarin (Coumadin), anisindione (Miradon) and other anticoagulant drugs prescribed to help prevent blood clots can be impacted by taking supplements. Because it can be affected by a large number of herbs, supplements and foods, it's important to consult your physician before taking any supplement with warfarin.

Below are some examples of supplements that may potentially interact with warfarin. Some increase or decrease the breakdown warfarin in the body, which, correspondingly, may reduce or increase the effects of warfarin. Others have their own blood-thinning or clot-promoting effects, which, correspondingly, may increase or reduce the effectiveness of warfarin. More details can be found by clicking on the links below.

Supplements that may increase warfarin's blood-thinning effect by inhibiting its breakdown include:

• Bee pollen
• Berberine/goldenseal
• Black pepper extract (piperine or Bioperine) — a bioavailability enhancer in some curcumin and CoQ10 formulas
• CBD (cannabidiol)
• Grapefruit juice
• Kava
• Kratom
• Milk thistle
• Quercetin

Supplements that may increase warfarin's blood-thinning effect due to their own blood-thinning effect include:

• Ashwagandha
• Chamomile
• Chondroitin
• Cinnamon (high-dose)
• Cranberry
• Curcumin
• Digestive enzymes (i.e. papain and bromelain)
• Fish oil
• Garlic
• Ginger
• Gingko
• Melatonin
• Nattokinase
• Resveratrol
• Saffron (including extracts such as Krocina)

Supplements that may reduce warfarin's blood-thinning effect by increasing its breakdown include:

• CoQ10
• Echinacea
• Ginseng
• St. John's wort

Supplements that may promote clot formation, reducing the blood-thinning effects of warfarin, include the following:

• Green tea
• Moringa leaf extract
• Vitamin K