What Tea Can I Drink While on Blood Thinners?

October 9, 2025 •

4 min read

Millions of people in the United States use blood thinners to prevent dangerous blood clots [1.3.5]. If you're one of them, you may be asking, what tea can I drink while on blood thinners? Understanding potential interactions is key to enjoying tea safely.

Quick Summary

When taking blood thinners, some teas can pose risks. Green tea contains Vitamin K, which can affect warfarin [1.2.2]. Many herbal teas like ginger, turmeric, and chamomile have natural blood-thinning properties that may increase bleeding risk [1.5.1, 1.6.1].

Key Points

Consult Your Doctor: Always talk to your healthcare provider before drinking new teas, especially herbal ones, while on blood thinners [1.9.4].
Green Tea & Warfarin: Green tea contains Vitamin K, which can make warfarin less effective if consumed in large, inconsistent amounts [1.4.1].
Herbal Tea Risks: Many herbal teas like ginger, turmeric, and chamomile have natural blood-thinning properties that can increase bleeding risk [1.5.1, 1.6.1].
Safer Options: Black tea and rooibos tea are generally considered safer options with a lower risk of interaction [1.2.1, 1.9.4].
Consistency is Key: For those on warfarin, maintaining a consistent daily intake of any tea (like green tea) is more important than complete avoidance [1.2.1].
Monitor for Symptoms: Be aware of signs of increased bleeding, such as easy bruising or unusual nosebleeds, and report them to your doctor [1.7.1].
Supplements vs. Tea: Concentrated herbal supplements (like turmeric capsules) pose a much higher risk of interaction than brewed teas [1.8.2, 1.8.3].

Understanding Blood Thinners and Tea Interactions

Anticoagulant medications, commonly known as blood thinners, are essential for preventing and treating blood clots. They work by interfering with the body's clotting process. However, their effectiveness can be altered by various foods, drinks, and supplements, including many popular teas [1.8.1]. The primary concerns are twofold: some teas can decrease the medication's effectiveness, raising the risk of clots, while others can amplify its effect, increasing the risk of dangerous bleeding [1.3.2, 1.7.1]. It is crucial to consult a healthcare provider before adding any new herbal products to your routine [1.9.4].

The Vitamin K Factor: Green Tea and Warfarin

For those taking warfarin (Coumadin), the main interaction concern with tea involves Vitamin K [1.2.2]. This vitamin plays a vital role in blood clotting, and warfarin works by inhibiting it [1.4.2, 1.4.5]. Green tea leaves contain a significant amount of Vitamin K [1.4.1]. While brewed green tea is not typically a major source, consuming large quantities (e.g., half a gallon or more daily) can introduce enough Vitamin K to counteract warfarin's effects and lower your INR (International Normalized Ratio), a measure of blood clotting time [1.3.1, 1.4.1]. Black tea, which is fermented, has no known significant interactions with warfarin and is often considered a safer alternative [1.2.1]. The key for warfarin users who drink green tea is consistency; a stable daily intake allows for medication dosage to be adjusted accordingly [1.2.1].

Herbal Teas with Natural Blood-Thinning Properties

Beyond the Vitamin K issue, many herbal teas contain compounds that have their own anticoagulant or antiplatelet properties. When combined with prescription blood thinners like apixaban (Eliquis) or warfarin, these teas can dangerously increase the risk of bleeding [1.7.1, 1.8.5].

Herbs to be cautious with include:

Ginger: Contains salicylates and may reduce platelet aggregation [1.5.1]. It has been reported to potentially increase bleeding risk with warfarin and other blood thinners [1.3.3, 1.7.3].
Turmeric: Its active compound, curcumin, has anticoagulant properties [1.5.1, 1.8.2]. Taking turmeric, especially in concentrated supplement form, with blood thinners can heighten the risk of bleeding [1.8.1, 1.8.4].
Chamomile: Contains coumarins and has shown mild blood-thinning effects, especially in high doses over a long time [1.6.1, 1.6.6]. It may increase bleeding risk in patients on warfarin [1.3.3].
Ginkgo Biloba: Known to inhibit platelet aggregation and can increase bleeding risk when taken with antiplatelet drugs [1.3.3, 1.5.1].
Dong Quai: Also known as "female ginseng," it contains coumarin and has been shown to increase bleeding risk with warfarin [1.3.3, 1.5.1].
Feverfew: This herb can inhibit platelet aggregation, and caution is advised for those on blood-thinning medications [1.3.3, 1.5.1].

Comparison of Common Teas and Their Risk with Blood Thinners


Tea Type	Potential Risk	Interaction Mechanism	General Guidance
Green Tea	Moderate (especially with Warfarin)	Contains Vitamin K, which can counteract warfarin [1.3.4]. Also has compounds that may increase bleeding risk with other thinners [1.3.2].	Drink in moderation and maintain a consistent intake. Avoid large quantities [1.4.1].
Black Tea	Low	Generally considered safe and does not have significant Vitamin K content or known interactions with warfarin [1.2.1, 1.2.2].	A safer alternative to green tea for those on warfarin [1.2.2].
Ginger Tea	Moderate to High	Has natural antiplatelet (blood-thinning) properties [1.5.1]. Can increase bleeding risk when combined with medications like Eliquis or warfarin [1.7.1].	Use with caution and consult your doctor. Avoid large amounts [1.7.3].
Turmeric Tea	Moderate to High	Curcumin is a natural anticoagulant [1.5.3]. Can significantly increase bleeding risk with blood thinners [1.8.1, 1.8.4].	Consult your doctor before using, especially in concentrated forms [1.8.3].
Chamomile Tea	Low to Moderate	May have mild blood-thinning effects, especially in high doses [1.6.1]. Can increase bleeding risk with warfarin [1.3.3].	Generally safe in moderation (1-2 cups), but discuss with your doctor if consumed regularly [1.6.2].
Rooibos Tea	Very Low	Generally considered safe as it does not contain significant Vitamin K and is caffeine-free [1.9.4].	Considered a safe option, but it's always best to inform your healthcare provider [1.9.4].
Peppermint Tea	Caution Advised	One case report noted a possible interaction with warfarin leading to elevated INR and bleeding [1.3.5].	Due to limited data and a potential risk, consult a doctor before regular consumption [1.3.5].

Making Safe Choices

The safest approach is always to communicate with your healthcare provider. Before you start drinking any new type of tea, especially herbal varieties, discuss it with your doctor or pharmacist. They can provide personalized advice based on your specific medication, dosage, and overall health profile. For those on warfarin, regular INR monitoring is essential to detect any changes caused by diet or supplements [1.2.1]. For all blood thinners, be vigilant for signs of increased bleeding, such as unusual bruising, nosebleeds, or blood in stool, and seek medical attention if they occur [1.7.1, 1.8.5].

Conclusion

So, what tea can you drink while on blood thinners? While some teas like rooibos and black tea are generally considered low-risk, others pose a significant potential for interaction [1.2.1, 1.9.4]. Green tea requires consistency for warfarin users, and many popular herbal teas like ginger, chamomile, and turmeric must be approached with extreme caution due to their natural blood-thinning effects [1.5.1, 1.6.1, 1.4.1]. The most critical step is to maintain an open dialogue with your healthcare provider, ensuring your love for tea doesn't compromise the safety and effectiveness of your medication.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before making any changes to your diet or medication regimen.

Authoritative Link: Review of herbal medications with the potential to cause bleeding

Frequently Asked Questions

You may be able to drink green tea in moderation while on warfarin, but consistency is crucial. Green tea contains Vitamin K, which can counteract warfarin. Drinking large or inconsistent amounts can affect your INR levels. It is best to discuss your intake with your doctor [1.2.1, 1.3.2].

You should be very cautious with teas that have natural blood-thinning properties, such as those containing ginger, turmeric, ginkgo biloba, and dong quai, as they can increase your risk of bleeding [1.5.1, 1.7.2]. Always consult a healthcare provider.

Chamomile tea has mild blood-thinning properties and may increase bleeding risk, especially when taken in high doses or with warfarin [1.3.3, 1.6.1]. Moderate consumption of 1-2 cups per day is likely safe, but you should inform your doctor [1.6.2].

You should use caution. Ginger has natural antiplatelet properties and may increase the risk of bleeding when taken with blood thinners like Eliquis [1.7.1, 1.7.3]. It's recommended to limit your consumption and discuss it with your doctor.

Rooibos tea is generally considered a safe option for people on blood thinners. It does not contain significant amounts of Vitamin K and is caffeine-free [1.9.4]. However, it's still a good practice to let your doctor know you are drinking it.

Black tea is generally considered safe and has no known significant interactions with warfarin or other common blood thinners [1.2.1]. It is often recommended as a safer alternative to green tea for those on warfarin [1.2.2].

The main risk with green tea, particularly for warfarin users, is its Vitamin K content, which can reduce the drug's effectiveness [1.4.1]. The risk with many herbal teas (like ginger or turmeric) is that they have their own blood-thinning properties, which can dangerously amplify the medication's effect and increase bleeding risk [1.5.1].