Green Tea and Omeprazole: Do They Increase Side Effects When Combined?

Based on current official drug information, green tea is not listed as a known interaction with omeprazole, and there is no established evidence that drinking green tea while taking omeprazole increases the risk of side effects. Official labeling highlights interactions with certain prescription medicines and specific herbal products (notably St. John’s wort), but does not include green tea or tea catechins. ^{[1] [2]}

---

What Omeprazole Interacts With

• Medicines affected by stomach acidity changes: Omeprazole raises stomach pH, which can alter how some drugs dissolve and are absorbed. This mechanism is noted for certain antiretrovirals and other sensitive medicines, but green tea is not among the listed concerns. ^{[3] [4]}
• Medicines processed by CYP2C19: Omeprazole can increase levels of drugs that rely on the liver enzyme CYP2C19 by inhibiting this enzyme over time; again, this applies to specific prescription medicines rather than common beverages like green tea. ^{[3] [5]}
• Specific herbal products: The consumer and professional labels consistently flag St. John’s wort as an herbal interaction of concern with omeprazole. Green tea is not mentioned. ^{[1] [2]}

---

What This Means For Green Tea

• No official warning: Current official sources do not warn against green tea with omeprazole. This suggests that typical dietary consumption of green tea is unlikely to raise omeprazole-related side effects. ^{[1] [6]}
• Practical approach: If you enjoy green tea, drinking it in moderation while on omeprazole would generally be considered acceptable, as long as you avoid known interacting agents like St. John’s wort and certain prescription medicines without medical guidance. ^{[1] [2]}

---

Possible Theoretical Considerations

• Caffeine sensitivity: Some people experience jitteriness, stomach discomfort, or sleep issues with caffeine; omeprazole itself does not amplify caffeine effects, but if you are sensitive, you might attribute symptoms to the combination when they are more likely due to caffeine alone. Official labels do not describe a caffeine–omeprazole interaction. ^{[1] [2]}
• Timing of doses: Omeprazole works best when taken 30–60 minutes before a meal; drinking green tea closely around the dose does not have a documented interaction, but keeping a consistent routine helps ensure reliable acid control. This timing strategy is standard practice reflected in consumer labeling, though not specific to green tea. ^{[7] [8]}

---

When To Be Cautious

• If you take high-risk medicines: If you are on medicines known to interact with omeprazole such as clopidogrel, methotrexate, certain antibiotics (clarithromycin, amoxicillin), or rifampin focus on those interactions rather than green tea, and follow prescriber guidance closely. ^{[1] [2]}
• If you use herbal supplements: Avoid St. John’s wort with omeprazole due to documented interaction risk, and always inform your clinician about any supplements. ^{[1] [2]}

---

Key Takeaway

There is no official evidence that green tea increases omeprazole side effects or causes a clinically significant interaction. The main documented concerns with omeprazole involve certain prescription drugs and specific herbal products like St. John’s wort not green tea. If you experience new or unusual symptoms, consider individual caffeine sensitivity or unrelated factors, and discuss them with your healthcare professional. ^{[1] [3] [2] [4]}