Based on NIH | Does drinking green tea at night interact with Amoxicillin or reduce its effectiveness?

Most official drug information does not list a known interaction between green tea and amoxicillin, and there is no widely accepted clinical evidence that typical green‑tea drinking reduces amoxicillin’s effectiveness in people. ^{[1] [2]} However, a single mouse study reported that concentrated green tea extract appeared to weaken amoxicillin’s antibacterial effect against MRSA, so it may be reasonable to avoid taking amoxicillin at the exact same time as highly concentrated green‑tea products. ^[3]

What the evidence says

• Official prescribing information for amoxicillin focuses on interactions with other antibiotics (for example, chloramphenicol, macrolides, sulfonamides, tetracyclines) and with hormonal contraceptives, and does not list tea or green‑tea catechins as a known interaction. ^{[1] [4]}
• Consumer guidance also does not flag green tea as a specific interaction with amoxicillin, though it notes the general issue of reduced efficacy of hormonal birth control while on amoxicillin. ^[2]
• An animal experiment in mice found that green‑tea extract (at 5% given enterally) increased the ED50 of amoxicillin against methicillin‑resistant Staphylococcus aureus, suggesting a weaker antibiotic effect in that model; the authors concluded that tea drinking was not recommended together with amoxicillin in that context. ^[3]
• On the other hand, laboratory and review data show green‑tea catechins can have antimicrobial activity and sometimes “synergize” with certain antibiotics in vitro, but human clinical data are lacking and results may differ by organism and conditions. ^{[5] [6]}

Practical guidance for taking amoxicillin with green tea

• Based on current authoritative labeling, drinking moderate amounts of brewed green tea is unlikely to meaningfully reduce amoxicillin’s effectiveness for most common infections. ^{[1] [4]}
• To be cautious, you might separate amoxicillin doses from tea (and especially from concentrated green‑tea extracts or supplements) by 1–2 hours, which can minimize any theoretical interaction and avoid potential effects on absorption.
• Avoid very high‑dose green‑tea extracts while on antibiotics unless advised by a clinician, since concentrated products were used in the mouse study that showed a negative effect. ^[3]

Other important points while on amoxicillin

• Some antibiotics, including amoxicillin, may decrease the effectiveness of combined hormonal birth control due to effects on gut flora, so consider a backup method during the antibiotic course. ^{[1] [2]}
• Certain antibiotics taken together can blunt each other’s action; this is noted for tetracyclines, macrolides, sulfonamides, and chloramphenicol with penicillins in vitro, though the clinical importance is not always clear this is more about prescription drug combinations than tea. ^{[1] [4]}

Bottom line

• There is no established, clinically proven interaction between regular brewed green tea and amoxicillin in humans according to standard drug references. ^{[1] [4]}
• A single animal study using concentrated green‑tea extract suggested a possible reduction in amoxicillin’s effect against MRSA, so spacing doses and avoiding high‑dose green‑tea supplements during therapy seems like a sensible precaution. ^[3]
• If you are on amoxicillin for a serious infection or have been advised to avoid certain beverages, it may be safest to drink water with your antibiotic and have green tea at another time of day.