Is it safe to drink green tea with aspirin?

In most cases, drinking moderate amounts of green tea while taking aspirin is considered low risk, and there is no well‑documented direct interaction that clearly increases harm. However, there are a few practical cautions: aspirin already thins the blood, so combining it with anything that may irritate the stomach or affect clotting can theoretically increase bleeding risk, and green tea contains caffeine which may worsen aspirin‑related stomach upset in some people. It’s reasonable to keep intake moderate (for example, 1–2 cups per day), take aspirin with food if your clinician allows, and monitor for warning signs like black stools or easy bruising.

What we know about green tea and drug interactions

• Green tea can alter how some medicines are absorbed or metabolized (processed) in the body, including effects on certain enzymes and transporters; these effects are drug‑specific and not proven to meaningfully impact aspirin. ^{[1] [2] [3]}
• Large amounts of green tea have been discussed in relation to blood thinners, mainly through vitamin K content; the concern is more relevant to warfarin than to aspirin, and applies to very high volumes (about 0.5–1 gallon per day). ^{[4] [5]}

Aspirin’s key risks to keep in mind

• Aspirin can increase the risk of gastrointestinal (GI) irritation and bleeding; this risk rises when combined with other agents that affect clotting or the stomach lining. ^{[6] [7]}
• Some herbs and supplements can add to bleeding risk when combined with aspirin; while green tea is not classically listed among the highest‑risk supplements, caution with combinations is sensible if you have bleeding risk factors. ^{[8] [6]}

Caffeine considerations

• Green tea contains caffeine, which can cause nervousness, irritability, sleeplessness, or a rapid heartbeat if you consume a lot or combine with other caffeine sources; minimizing total daily caffeine may help, especially if you’re sensitive or if aspirin already upsets your stomach. ^{[9] [10] [11]}

Practical guidance

• Aim for moderation: 1–2 cups of brewed green tea per day is generally reasonable for most adults on aspirin, unless your clinician has advised otherwise.
• Take aspirin with food (if appropriate for your regimen) to reduce stomach upset, and avoid taking it on an empty stomach alongside strong tea. ^{[12] [13]}
• Limit other caffeine sources (coffee, energy drinks, caffeine tablets) on days you drink green tea to reduce jitteriness and stomach irritation. ^{[9] [10]}
• Be alert for warning signs of bleeding: black/tarry stools, vomiting blood, unusual bruising, nosebleeds that are hard to stop, or dizziness seek medical care if these occur. ^{[6] [7]}
• If you also take other medicines that raise bleeding risk (for example, other NSAIDs like ibuprofen or naproxen, certain antidepressants, steroids, or blood thinners), discuss green tea intake with your clinician and consider further limits. ^{[6] [14]}

When to be extra cautious or avoid

• History of stomach ulcers, GI bleeding, or gastritis. ^[6]
• Concurrent use of multiple antiplatelet/anticoagulant drugs (for example, aspirin with clopidogrel or warfarin). ^[7]
• Very high green tea consumption (approaching 0.5–1 gallon per day) or use of concentrated green tea extracts, which have more variable effects and have been linked to other drug interactions. ^{[4] [2]}

Bottom line

• Moderate brewed green tea is generally compatible with aspirin for most people. There is no strong evidence of a harmful direct interaction, but due to aspirin’s bleeding risk and green tea’s caffeine, it’s wise to keep intake modest, take aspirin with food when appropriate, avoid excessive caffeine, and watch for bleeding symptoms. ^{[6] [7] [9] [10] [4] [2]}