What are the side effects of drinking excess amount of tea?

Tea Side effects
Tea Side effects

One of the most beloved beverages is tea. There are different types of teas, but some of the most popular include oolong, black and green tea. All of these types are made from the leaves of the Camellia sinensis plant. Teas can make wonders for our overall health. They can help us to lose weight. When tea is brewed right, then you can experience a lot of positive side effects when you drink it on daily basis. Few things are as calming or enjoyable as a drinking hot mug of tea, but the merits of this beverage do not stop there.

tea side effects
tea side effects

In many different traditional medicines, tea has been used as a natural treatment for many different diseases. Some modern studies are shown that plant compounds in teas can help to reduce your risk of chronic conditions, such as heart disease, diabetes, obesity, and cancer [1,2]. Moderate tea consumption is a very healthy choice for most people. But, if you drink too much tea, like 3 – 4 cups per day (710 – 950 ml) per day could have some side effects on your health.

Side effects of tea:

Here you can see some negative side effects from drinking too much tea:

Caffeine dependence:

We know that caffeine is a habit-forming stimulant. The regular intake of tea or other sources could lead to dependence. Some symptoms of caffeine withdrawal include fatigue, increased heart rate, irritability, and headache. The level of dependence is different and it depends on a person. But, some studies have said that caffeine dependence could start after as few as three days of consecutive intake, with increased severity over time. [3]


In a few cases, people have reported that they are feeling light-headed or dizzy after drinking tea. But, it can be a result of drinking too much caffeine from tea. Usually, this symptom is associated with a large dose of caffeine, typically which is greater than 400 – 500 mg or approximately 6 – 12 cups worth of tea. But, also it can happen with smaller doses in people who are particularly sensitive to it. [4]

Usually, it is not recommended to consume that much tea in one sitting. If you have noticed that you often feel dizzy after you drink tea, then you should opt for a lower caffeine version or talk with your doctor about which type of tea could be safe for your health.


Intermittent caffeine is helpful for relieving some types of headaches. But, when it is used chronically, then opposite effects can happen. Nonstop consumption of caffeine from tea can lead to recurrent headaches. In some studies are shown that little as 100 mg of caffeine on daily basis can lead to daily headache recurrence. But, the specific chunk needed to trigger a headache can alter based on the individual’s tolerance.

Tea is usually lower in caffeine compared to other popular types of caffeinated beverages, such as coffee or soda. But, some types can still provide as much as 60 mg of caffeine per one cup. If you have recurrent headaches and you think that they are related to your tea intake, then you should try to reduce or eliminate this beverage from your diet for a while to see if your symptoms will improve.

Pregnancy complications:

When a pregnant woman exposes herself to high levels of caffeine from beverages, like tea, this can increase her risk of complications, such as low infant birth weight and miscarriage. Results from the dangers of caffeine during pregnancy are mixed and it is still not known how much is safe. But, some studies have said that the risk of complications is relatively low if you keep your daily caffeine intake under 200 – 300 mg. In one American study is not recommended to exceed more than 200 mg of caffeine. [5]

The total caffeine intake can vary, but usually, it falls between 20 – 60 mg per cup. Also, on the safe side of caution, it is not recommended to drink more than 3 cups of tea per day. Some people, want to drink caffeinated–free herbal teas in place of regular tea, so they will avoid caffeine exposure, especially during pregnancy. But, not all types of herbal teas are considered safe during pregnancy.

Some herbal teas can have licorice or black cohosh which can induce labor prematurely and they should be avoided. If you are pregnant and you are concerned about your herbal or caffeine tea intake, then you should talk with your doctor about recommended safe dosages and safe herbal teas.


The caffeine in tea can lead to heartburn or can aggravate preexisting acid reflux symptoms. In studies are found that caffeine can relax the sphincter which separates the esophagus from the stomach, allowing the stomach contents to more easily flow into the esophagus. Also, caffeine can lead to increased stomach acid production. But, drinking tea does not mean that it will cause you heartburn for sure. [6]

Individuals are reacting very separately to the same foods. If you consume large amounts of tea and you have heartburns frequently, then you can reduce your intake and you will see if your symptoms will improve.

Reduced iron absorption:

Tea is rich in tannins which can bind to iron in some foods and this makes it unavailable for iron to be absorbed in your digestive tract. It has been shown that tannins in tea are more likely to hinder the absorption of iron from plant sources than animal-based foods. The exact amount of tannins can vary considerably depending on the type and how it is prepared. This is a reason why you should limit your intake to three or fewer cups per day.


There are some compounds in tea that can lead to nausea, especially when it is consumed on an empty stomach or in large amounts. Leaves of teas have tannins which are responsible for the bitter and dry taste of tea. Tannins have astringent nature which can irritate the digestive tissue, potentially leading to uncomfortable symptoms, such as stomach ache or nausea. The amount of tea that is needed for a person to have this side effect varies from one person to another.

People, who are more sensitive, can experience these symptoms after drinking one to two cups of tea. While other people may be able to drink more than five cups of tea without noticing any side effects. If you notice some of these symptoms after drinking tea, then you can reduce the amount of tea that you drink at any one time. Also, you can have some food with your tea or add a splash of milk to your tea. Tannins can bind to carbs and proteins in food and this can minimize digestive irritation. [7]

Poor sleep:

Tea naturally has caffeine. The excessive intake of tea can disrupt your sleep cycle. Melatonin is a hormone which is signaling our brain that it is time to sleep. In some studies are found that caffeine may inhibit melatonin production, which is resulting in poor sleep quality. When you do not have enough sleep, then it can lead to many health problems, like reduced attention span, impaired memory, and fatigue. Also, chronic sleep deprivation is associated with an increased risk for obesity and poor blood sugar control. People metabolize caffeine at different rates.

It is difficult to predict exactly how it impacts sleep patterns in everyone. In some studies are found that even just 200 mg of caffeine consumed six or more hours before bedtime can negatively affect sleep quality. But, other studies have observed no significant effect. If you regularly drink caffeinated tea and you experience symptoms related to poor sleep quality, then you may want to reduce your tea intake, especially if you consume other caffeinated beverages or supplements.

Increased anxiety, stress, and restlessness:

Leaves of teas have natural caffeine. When you overconsume caffeine, no matter the source can lead to feelings of restlessness, stress, and anxiety. On average cup of tea, there is 11 – 61 mg of caffeine, which depends on the variety and brewing method. Black tea has more caffeine compared to green and white tea. The longer you steep your tea, the higher is its caffeine content. In some analyses is said that caffeine quantity beneath 200 mg on daily basis is unlikely to cause significant anxiety in most people.

But, some people are more sensitive to the effects of caffeine than others and you may need to limit your intake further. If you notice that when you drink tea makes you feel nervous or jittery, then it could be a sign that you have had too much and you feel nervous or jittery, then it could be a sign that you have had too much and you want to cut back to reduce symptoms. [8]


[1] Chacko SM, Thambi PT, Kuttan R, Nishigaki I. Beneficial effects of green tea: A literature review. Chinese Medicine. 2010;5:13. doi:10.1186/1749-8546-5-13

[2] Yang CS, Hong J. Prevention of chronic diseases by tea: Possible mechanisms and human relevance. Annual Review of Nutrition. 2013;33:161-81.

[3] Tseng HC, Wang CJ, Cheng SH, et al. Tea-drinking habit among new university students: Associated factors. The Kaohsiung Journal of Medical Sciences. 2014;30(2):98-103.

[4] Felipe L, Simoes LC, Goncalves DU, Mancini PC. Evaluation of the caffeine effect in the vestibular test. Brazilian Journal of Otorhinolaryngology. 2005;71(6):758-62.

[5] National Institutes of Health. Moderate daily caffeine intake during pregnancy may lead to smaller birth size. 2021. Retrieved from www.nih.gov/news-events/news-releases/moderate-daily-caffeine-intake-during-pregnancy-may-lead-smaller-birth-size

[6] Kim J, Oh SW, Myung SK, et al. Association between coffee intake and gastroesophageal reflux disease: a meta-analysis. Diseases of the Esophagus. 2014;27(4):311-7. doi:10.1111/dote.12099.

[7] Higdon JV, Frei B. Coffee and health: A review of recent human research. Critical Reviews in Food Science and Nutrition. 2006;46(2).

[8] Richards G, Smith A. Caffeine consumption and self-assessed stress, anxiety, and depression in secondary school children. Journal of Psychopharmacology. 2015;29(12):1236–47. doi:10.1177/0269881115612404


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