Can green tea cause diarrhea? (+3 health benefits)

In this article, we will answer the question “Can green tea cause diarrhea?”, and what are some side-effects and benefits of drinking green tea?

Can green tea cause diarrhea?

Yes, green tea can cause diarrhea if consumed in large enough amounts. Two compounds present in green tea, caffeine, and strictinin, have been found to have laxative effects. They increase the gut movements or stimulate the relaxation of the colon, resulting in more trips to the bathroom. The symptoms are worse in patients with IBS.

The laxative effects are more pronounced if the person is suffering from an acid reflux disease, or has a stomach ulcer. As a precaution, never drink green tea on an empty stomach and limit its consumption to only one cup per day.

Brew your green tea in water no hotter than 180°F. The tannins released during brewing increase the stomach acidity which is reflected in acid reflux, nausea, and even constipation.

What is green tea?

Green tea comes from the Camellia sinensis plant, the same plant from which oolong, white and black tea are obtained. Green tea is long known for its exceptional medicinal properties. 

Green tea is the least processed of all teas, hence, it retains much of the polyphenol and other nutrients. The fresh green leaves of the Camellia plant are steamed under high temperatures instead of fermentation to make green tea.

Epigallocatechin gallate (EGCG), l-theanine, potassium, iron, calcium, and caffeine are some of the bioactive compounds of green tea. Green tea provides 8mg of caffeine for every 8-ounces.

Some side-effects of drinking green tea


The caffeine content of green tea can trigger headaches in people suffering from migraines or frequent headaches.

Troubled sleep

The caffeine in green tea inhibits the production of melatonin, depriving the person of sleep. The symptoms are worse for caffeine-insensitive people.  L-theanine, a compound present in green tea, has been found to promote alertness.

Iron deficiency

The tannins in green tea inhibit the absorption of iron from the gut. This is particularly dangerous for anemic people. To solve this problem, add lemon to your tea or drink at least 1 hour after or before a meal.


Due to excessive green tea intake, the tannins can cause nausea, constipation, and vomiting. Limit its use to 1-2 cups per day.


Although it’s rare, green tea can cause dizziness and convulsions when consumed in large amounts due to the caffeine. It does so by increasing blood flow to the brain that causes motion sickness. Do not drink if you are a patient of Tinnitus or caffeine sensitivity.

Bleeding disorders

Green tea inhibits the oxidation of fatty acids and reduces the levels of fibrinogen in the blood, resulting in thinner blood.

Liver disease

When consumed in excessive amounts, the caffeine in green tea can damage the liver.

Heart diseases

Green tea has been found to raise blood pressure and disrupt the heart rhythms either to the caffeine content or by interfering with blood pressure medications.

Bone health

Green tea inhibits calcium deposition in the bones, resulting in osteoporosis.

A risk for pregnant women

Drinking green tea in excessive amounts can lead to miscarriage and birth defects in newborns while compromising the health of the mother. It should be consumed in moderate amounts due to the presence of Tannins, caffeine, and tea catechin.

Other side-effects

The caffeine in green tea can cause anxiety and affects blood sugar levels. Therefore, people with anxiety and diabetes should limit their use of green tea. Green tea increases the pressure within the eye leading to Glaucoma. Green tea can also lead to skin conditions like eczema and hives.

Other FAQs about Tea which you may be interested in.

Do tea bags get old?

Do tea bags go bad?

How to bottle tea?

Benefits of drinking green tea

Helpful for weight loss

The caffeine and catechins present in Green tea boost metabolism and promote the oxidation of fat cells, hence, aiding in weight loss.

Promotes mental alertness

The caffeine present in green tea, at the rate of 2-4%, helps in mental alertness. It does so by stimulating the heart, muscles, and brain to release neurotransmitters. It also promotes urine production. It also helps to prevent Alzheimer’s and Parkinson’s’.

Protects against heart diseases and cancer

Green tea contains some flavonoids namely; epigallocatechin gallate, or EGCG, that have excellent anti-oxidant properties. These antioxidants fight free radicals and protect the body against heart diseases. It also lowers the LDL and improves the blood flow in vessels to prevent the risk of heart diseases.

The polyphenols present in green tea have anti-inflammatory properties. Moreover, they prevent joint degeneration, fight the Human Papilloma Virus(HPV), and prevent Cervical Dysplasia and Prostate Cancer.


In this article, we answered the question “Can green tea cause diarrhea?”, and what are some side-effects and benefits of drinking green tea?


Hello, I'm Sana Ameer. I'm a student of Food Science and Technology at UVAS. I like to bake and I aspire to become a Food blogger.