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Published on: 2/25/2026
Yes, green tea can make some people feel sick, and there are several factors to consider. Most problems trace to tannins, acidity, and caffeine causing nausea or reflux, headaches or jitteriness, reduced iron absorption, medication interactions, and rare liver injury from high dose extracts, with risk higher if you drink it on an empty stomach, overconsume, have GERD, or use supplements; see below to understand more.
Medically approved next steps include pausing it, avoiding empty stomach use, diluting or limiting intake, skipping concentrated extracts, and seeking care for red flags like severe abdominal pain, black stools, jaundice, or persistent symptoms, and talking to your doctor if you take prescription medications; full details and which steps fit your situation are outlined below.
Green tea is one of the most widely consumed beverages in the world. It's praised for its antioxidants, metabolism support, heart health benefits, and potential role in reducing inflammation. For most people, green tea is safe and even beneficial when consumed in moderation.
But if you've noticed nausea, stomach pain, headaches, or other uncomfortable symptoms after drinking green tea, you're not imagining it. In some situations, green tea can make you feel sick.
Let's break down what the science says, who may be at risk, and what medically approved next steps you should consider.
Green tea comes from the Camellia sinensis plant and is rich in:
Research suggests green tea may:
For most healthy adults drinking 2–3 cups per day, green tea is considered safe.
However, more is not always better.
Yes, in certain cases, green tea can cause symptoms. The most common issues are related to caffeine content, acidity, tannins, and concentrated extracts.
This is the most common complaint.
Green tea contains tannins, which can:
You may notice:
Drinking green tea first thing in the morning without food is a common trigger.
If you're experiencing persistent stomach issues and want to understand what might be causing them, you can use a free Abdominal Discomfort symptom checker to get personalized insights in minutes.
Green tea can relax the lower esophageal sphincter slightly and increase stomach acid production. For people with:
Green tea may worsen symptoms.
You might notice:
Switching to low-caffeine or diluted green tea sometimes helps.
Green tea contains less caffeine than coffee, but it still contains caffeine.
If you're sensitive, it can cause:
Caffeine sensitivity varies widely. Some people react to even small amounts.
This is important.
Drinking brewed green tea in normal amounts is generally safe. However, high-dose green tea extract supplements have been linked in rare cases to liver injury.
Medical literature has documented:
Warning signs include:
If you experience these symptoms, seek medical care immediately. This is not something to monitor at home.
Green tea tannins can reduce iron absorption from plant-based foods.
This matters most if you:
Drinking green tea between meals instead of with meals can help reduce this effect.
Green tea may interact with certain medications, including:
If you take prescription medication, ask your doctor or pharmacist whether green tea is safe for you.
You may be more sensitive if you:
For these individuals, even a "healthy" beverage like green tea can cause discomfort.
Most research suggests:
Green tea extracts are more concentrated and carry more risk than brewed tea.
If green tea is making you feel unwell, here's what to do:
If symptoms resolve after stopping, green tea may be the trigger.
Have it after meals to reduce irritation.
Try 1 cup per day instead of several.
Unless prescribed or approved by a healthcare provider, avoid green tea extract capsules.
Seek medical care if you experience:
These symptoms require prompt medical evaluation.
You should speak to a doctor if:
While green tea reactions are often mild, serious conditions can sometimes present with similar symptoms. It's better to get evaluated than to guess.
If anything feels severe, sudden, or life-threatening, seek urgent medical care immediately.
For most people, green tea is safe and offers meaningful health benefits. But it is not harmless for everyone.
Green tea can make you feel sick if:
The key is moderation and awareness of your body's signals.
If your symptoms are mild, adjusting how and when you drink green tea may solve the problem. If symptoms are persistent, severe, or concerning, speak to a doctor to rule out more serious causes.
Green tea is a powerful plant with real biological effects. Used wisely, it can support health. Used excessively or in the wrong context, it can cause problems.
Listen to your body. Adjust thoughtfully. And when in doubt, get medical guidance.
(References)
* Lambert JD, Lee MJ. Green tea catechins and liver injury: a review of the evidence from in vitro, animal, and human studies. Food Chem Toxicol. 2010 Sep;48(9):2484-93. doi: 10.1016/j.fct.2010.05.029. Epub 2010 May 29. PMID: 20500857.
* Mazzanti G, Di Sotto A, Vitalone A. Safety of green tea and green tea extracts in relation to their health claims. Nutr Res. 2009 Aug;29(8):525-36. doi: 10.1016/j.nutres.2009.06.002. PMID: 19700010.
* Zheng EX, Rossi S, Fontana RJ. Green tea extract-induced liver injury: a case series and systematic review. Aliment Pharmacol Ther. 2017 Oct;46(7):728-736. doi: 10.1111/apt.14231. Epub 2017 Aug 25. PMID: 28834928.
* Garcia-Cortes M, et al. Green Tea and the Risk of Hepatotoxicity: A Systematic Review and Meta-Analysis of Human Studies. Gastroenterology. 2021 Apr;160(5):1746-1763. doi: 10.1053/j.gastro.2020.12.040. Epub 2021 Jan 6. PMID: 33418049.
* Isomura Y, Aoi N, Sato K, Akagiri S. Adverse effects of green tea catechins: a critical review. Biosci Biotechnol Biochem. 2016 Aug;80(8):1501-8. doi: 10.1080/09168451.2016.1158655. Epub 2016 Feb 25. PMID: 26918804.
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