6 Side effects of drinking too much green tea

6 side effects of excess green tea consumption

It’s often said that green tea is efficient and beneficial when it comes to one’s health. This beverage has taken the world by storm and is considered one of the healthiest drinks today. However, excess green tea consumption can have negative side effects. Most of the side effects can be avoided by drinking green tea in moderation.  The main cause of these side effects is because of the caffeine present in it. 

It’s important to remember that everyone is different and some people may be more susceptible to some side effects than others. For example, someone with a genetic condition that affects their liver may be more sensitive to the effects of green tea than someone else. However, many of the side effects of green tea can occur for everyone. Here are some of the common side effects of drinking too much green tea:

It might lead to insomnia


Green tea can cause insomnia in some people. It may cause you to feel tired during the day and make you drowsy at night. As mentioned before, green tea has caffeine in it. Even though it is present in small amounts, people can get affected by it, thus triggering insomnia. Caffeine releases hormones like melatonin, which regulates the natural sleep cycle in humans. Green tea also contains l-theanine, a chemical that helps induce calm but also increases alertness and focus. This is something that may disrupt sleep for some individuals. Some research shows that l-theanine is beneficial for sleep; however, these studies have mainly been conducted on individuals with disorders including ADHD and schizophrenia.

May cause vomiting

Vomiting is another common effect of excess green tea consumption. This happens because green tea contains tannins which have been associated with triggering vomiting and nausea. Green tea contains antioxidants that hinder iron absorption in the human body, this is especially dangerous for people who suffer from anemia. It is important to regulate one’s green tea consumption, not more than 3 cups a day. To your cup of green tea, add lemon. The vitamin C in lemon promotes iron absorption, counteracting this side effect, thus smoothening and in most cases preventing vomiting. 

May cause headaches and nausea


Headaches and nausea are common side effects of consuming too much green tea. These side effects are caused by the caffeine in the tea. Most people drink about 5 to 6 cups of green tea per day. Caffeine is not usually absorbed into the bloodstream quickly. It will go through your liver and get metabolized there. That’s where it causes some headaches and nausea. To avoid this, do not drink green tea on an empty stomach, especially right after one wakes up. It is better to consume it after a meal.

May increase the risk of bone diseases

Excess consumption of green tea can lead to an increased risk of bone diseases such as osteoporosis, especially in women. This happens because of the compounds in the tea, which inhibit calcium absorption from the bloodstream. If by any chance an individual consumes more than 2 to 3 cups of green tea in a day, they should take calcium supplements to support their bone and skeletal health. 

May cause dizziness and convulsions

The caffeine in green tea decreases blood flow to the brain and CNS. This results in motion sickness and can lead to convulsions in many cases. Sometimes, green tea can also increase tinnitus aka ringing in the ears. Researches show that the maximum tolerated dose of green tea in humans is equal to 24 cups of the beverage. It is important to keep in mind that this is the maximum amount but one should not drink more than 2 to 3 cups a day to maintain good health. 

May pose threat to pregnancy


As mentioned before, green tea contains caffeine and tannins- these have been linked to increased risk during pregnancy. Caffeine is passed through breast milk. This means that the infant is also consuming caffeine which is extremely dangerous for the newborn. Research shows that drinking more than 2 cups per day leads to miscarriages and birth defects in children. It’s essential to consult a physician and keep the caffeine intake below 200 mg daily. 

Green tea has been considered the modern-age elixir for health problems. However, like anything in excess, green tea too can harm if consumed in large quantities. Most of the side effects are caused due to the presence of caffeine and tannins. Therefore, it is important to limit one’s green tea consumption. 

Disclaimer: It’s important to consult a professional before adding or eliminating anything from your diet. The above information should be used for reference purposes only and should not be used as an alternative to an expert’s advice.