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Answer:Certain herbal medications can interact with such blood thinners as Coumadin® (warfarin), Plavix® (clopidogrel), or aspirin. Many herbals contain ingredients called coumarins that act similar to the prescription medication warfarin and stop blood from clotting. Other herbals may affect how platelets (the cells responsible for blood clotting) function. Herbals also can affect blood thinners by preventing the drug from being broken down in the body, resulting in higher drug levels and a higher risk for bleeding.

If you take a blood thinner, it is important to talk with your doctor first before beginning any new medications—including over-the-counter items, vitamins, and herbals. Your doctor may need to do blood tests more frequently if you are on warfarin and are starting a new medication. Always watch for signs of bleeding, and call your doctor if you experience a lot of unexplained bruising, nosebleeds, or gum bleeding while brushing your teeth. More serious signs of bleeding that may require hospitalization can include coughing up blood, vomiting blood, or blood in the urine or stool.

Below is a partial list of:

Please note: Herbal medications are not required to undergo safety testing, as are prescription medications. Therefore, herbal medication interactions may not be known until a reaction has been reported. There may be other herbals not listed here that potentially could interact with blood thinners.

§ Coenzyme Q-10 § Cranberry § Dong quai (or Angelica) § Garlic § Ginger § Ginkgo § Ginseng § Glucosamine § Green tea § Lycium tea § Melatonin § Soy products § St. John's wort	§ Arnica § Bilberry § Chamomile § Cinchona § Clove oil § Evening primrose § Feverfew § Kava § Meadowsweet § Motherwort § Papaya § Pumpkin seed § Red clover § Saw palmetto

*NOTE: These are not complete lists. Be aware that—depending on which country you are from—certain herbals are known by names that are different from those listed above.

Check drug interactions on Walgreens.com.

View the Walgreens.com Ask a Pharmacist Archives for a list of all commonly asked questions.

DISCLAIMER: The information provided is not a substitute for medical advice. Consult your physician for diagnosis and treatment of your medical condition. Advances in medicine may cause this information to become outdated, invalid or subject to debate. Professional opinions and interpretations of the scientific literature may vary. Walgreens' terms of use and general warranty disclaimer apply to all services provided. If you are in need of immediate medical attention, contact your physician, poison control center or emergency medical professional. If you need to speak with a pharmacist for non-emergency matters, contact your local Walgreens pharmacist or call a Walgreens.com pharmacist toll-free at 1-877-250-5823.