Is Drinking Too Much Green Tea Bad for You?

In Asia, people have been drinking green tea for ages and always talk about its health benefits. There is no doubt that green tea is the healthiest and best hydrating drink. Also, it contains antioxidants that offer many potential health benefits that you cannot overlook. For that reason, many people have begun drinking green tea instead of coffee or cola to get their daily caffeine boost.

However, as with many health-giving products, if it consumed at high levels, then it will cause unpleasant and possibly even dangerous side effects. If you drink more than five cups of green tea per day, you may begin to experience some of these side effects.

Green tea’s rise in popularity isn’t limited to traditional cultures anymore—it has become a global wellness trend. From morning routines to detox diets, many people now see green tea as a symbol of a healthy lifestyle. Its polyphenols, especially catechins, are widely praised for supporting heart health, boosting metabolism, and even improving skin quality. Yet, while these benefits are impressive, balance is key. What most people overlook is that the same compounds responsible for these advantages can also stress the body when consumed excessively. Understanding both sides of this ancient drink helps you make smarter, more mindful choices about how much green tea is truly good for you.

Keep reading to discover more about the side effects of consuming too much green tea.

HOW I STARTED MY RESEARCH ABOUT THIS TOPIC

Last month, a customer asked me this question.

Is drinking too much green tea bad for me?

Since I knew very well about caffeine from my earlier research and article I wrote, I told the customer about the disadvantage of caffeine during the call.

After that, I thought I should see if there are another effect of drinking too much green tea.

As I research more, I find out some negative effects.  I almost stopped writing about the article once as you know I promote healthy green tea and I am drinking green tea because it makes me feel better and healthy. But I thought it is important to write about this and being honest with you.

During my research, I went through various scientific journals, health blogs, and medical studies to ensure every fact was backed by credible sources. What surprised me most was how often people assume that “natural” automatically means “harmless.” Many dietitians and researchers highlighted that even healthy drinks like green tea can affect the body differently depending on genetics, metabolism, and existing health conditions. Reading these studies gave me a new perspective—green tea isn’t the enemy, but rather a drink that requires moderation and understanding. That realization encouraged me to dig deeper and share what I discovered, even if it challenged my personal admiration for green tea.

As a green tea lover, this article was really hard to write, but I wanted to be true to the facts and science. 

This article is not my favorite one as a result but gives you important information about green tea when drink excessively.

EXCESSIVE CAFFEINE INTAKE IS HARMFUL TO HEALTH

Green tea is a caffeinated beverage and has many health benefits. It almost helps in all body functions and keeps you active and fresh all day. The caffeine levels vary from green tea brands to brand or types. To check the exact amount of caffeine in a green tea product, you should look at the packaging and check before buying.

Many major brands of green tea include approximately 35 milligrams of caffeine per tea bag. The consumption of between 200 and 300 milligrams of caffeine per day is useful and beneficial for health. However, less caffeine intake may cause stronger side effects for sensitive people, and it is always advised to confirm the amount before drinking.

On the other side, as you know, excess of anything is harmful in every way for the human body, and green tea is no exception. Green tea has caffeine, and excess of it is harmful to health. When you consume tea in more doses than intended, then it can cause a health problem. Such issues include:

An increase in heart rate

Though caffeine is present in a moderate amount in tea but can help in many ways, such as lowering blood pressure. However, it is not good for people with some heart problems; it causes irregular heartbeat in some people due to some compounds and also interferes with blood pressure medication. If you are thinking of consuming green tea, then it is a wise decision to seek your doctor about your heart problems first and then make a decision.

Additionally, it’s important to remember that caffeine affects everyone differently. Factors like age, body weight, and tolerance level determine how your body reacts to it. Some people might feel a quick energy boost and improved focus, while others could experience jitteriness or a racing heartbeat after just one or two cups. Consuming high doses of caffeine regularly can also lead to dependency—where your body becomes so used to caffeine that skipping your usual cup results in headaches, fatigue, or irritability. This cycle often pushes people to drink even more, unknowingly putting extra stress on their nervous system and heart. Therefore, being mindful of your total daily caffeine intake, including from coffee, chocolate, or energy drinks, is essential to maintaining overall health and balance.

An upset stomach

Green tea, if not taken with precaution, may cause stomach problems and would be harmful to health for those who already have stomach issues. It contains tannins that increase the level of acid in your stomach, and that may lead to digestive problems such as constipation, acid reflux, and nausea, etc. Moreover, if you brew it strong or take it on an empty stomach, then it will cause stomach irritation.

If you take it in excess amount, then caffeine present in tea produces laxative that stimulates the colon muscles, which in result contract and release more and causes upset stomach and diarrhea. The tea brewed with too hot water can worsen these problems, and it is advised to keep the water temperature between 160 to 180F.

 Also, to avoid most of these symptoms, takes green tea after one hour of a meal and in a small amount. Lastly, absolutely avoid it if you are already suffering from acid reflux disease because it will increase acidity.

Another factor many people overlook is the combination of green tea with certain foods or supplements. For instance, pairing it with iron-rich meals or vitamin supplements can sometimes worsen stomach discomfort because the tannins interfere with nutrient absorption, increasing acidity. Likewise, drinking multiple cups in quick succession can overwhelm your digestive system, especially if you already have a sensitive stomach or conditions like gastritis. To enjoy green tea safely, start with a milder brew and limit yourself to one or two cups a day, observing how your body reacts. Over time, you can adjust the strength or frequency to suit your comfort level. Listening to your body is the best way to enjoy the benefits of green tea without upsetting your digestive balance.

Increase in anxiousness

The high level of caffeine in the blood leads to a jittery feeling in body parts and anxiousness. In one way, it helps with a mild anxiety issue, but excess consumption may lead to worsening the condition. It is advised that if you are prone to anxiousness, then it is wise to monitor your daily green tea intake.

A licensed therapist from BetterHelp may also be able to help you manage your anxiety. 

Caffeine stimulates the central nervous system, which is why many people feel more alert and focused after drinking green tea. However, when consumed in excess, this stimulation can turn into restlessness, racing thoughts, and an elevated heart rate — symptoms that mimic or worsen anxiety. For individuals who are already dealing with stress or panic disorders, too much caffeine may interfere with relaxation and sleep, creating a cycle of fatigue and heightened tension. It’s also worth noting that caffeine sensitivity varies from person to person; some may handle several cups a day comfortably, while others may feel anxious after just one. To maintain balance, try switching to decaffeinated green tea or herbal teas in the afternoon and evening, which allow you to enjoy similar flavors and health benefits without the anxious side effects.

Restlessness

It can cause restlessness if you overdose the green tea because caffeine though present in a moderate amount, can still affect your nerves if taken in excess amount. To keep your nerves relax and active, you should keep your consumption mild.

Restlessness often appears when caffeine overstimulates the nervous system, making it difficult for your body and mind to fully relax. You might notice symptoms like fidgeting, muscle tension, or difficulty focusing — all signs that your body is struggling to process the extra caffeine. Drinking green tea too close to bedtime can also interfere with your natural sleep rhythm, leaving you feeling alert when you should be winding down. To prevent this, try limiting your intake to the earlier part of the day and balance it with plenty of water to stay hydrated. Choosing lighter brews or alternating between regular and decaffeinated green tea can also help you enjoy its refreshing qualities without disturbing your sense of calm and rest.

Tremors

Tremors, some call it jittery or trembling, feeling on parts of your body, which is caused by taking caffeine in large amounts. It is another prominent side effect along with others and happens if you drink green tea more than the safe quantity.

Tremors usually occur when caffeine overstimulates the brain’s motor cortex — the part responsible for muscle movement. This overstimulation can cause involuntary shaking or trembling in your hands, fingers, or even eyelids. While these tremors are temporary, they can be unsettling, especially if you rely on green tea throughout the day for energy. People with certain medical conditions, such as thyroid issues or anxiety disorders, may notice that these effects appear even at lower doses. To reduce the likelihood of tremors, spread your tea consumption across the day instead of drinking several cups in a short period. Pairing green tea with meals or snacks can also slow caffeine absorption and make its effects gentler on your nervous system.

Insomnia

The caffeine is known as a stimulant that activates your brain and nerves and keeps you on feet all day. It works the same evening green tea and keeps you up and active all day. However, if you drink too much or late in the day or at night, then it may lead to insomnia. If you already have sleeping problems, then avoid taking it late evening or at night, so your sleeping schedule does not disturb due to high caffeine in your blood.

Insomnia caused by green tea is one of the most common side effects linked to caffeine sensitivity. Because caffeine blocks adenosine — a brain chemical that promotes sleep — it can keep your mind alert long after you’ve finished your last cup. Even though green tea contains less caffeine than coffee, drinking multiple cups throughout the day or late in the evening can build up enough stimulation to interfere with your body’s natural sleep-wake cycle. You might find it harder to fall asleep or experience lighter, more restless sleep. To avoid this, try setting a “cutoff time” and avoid green tea at least five to six hours before bedtime. If you enjoy the flavor, opt for a decaffeinated or herbal version at night so you can still enjoy the soothing ritual without sacrificing your rest.

Withdrawal symptoms

It is good to build up a routine about healthy habits and stick to it. However, if you are routinely drinking green tea and suddenly stops, then you may experience withdrawal symptoms. Such symptoms include irritability, drowsiness, and headaches, etc.

These withdrawal symptoms occur because your body becomes accustomed to regular caffeine intake, and when that supply suddenly stops, the nervous system reacts to the change. The brain, which has adapted to caffeine’s stimulating effects, temporarily struggles to adjust, leading to fatigue, irritability, and mood swings. Some people may also experience difficulty concentrating or mild nausea during the first few days after quitting. Fortunately, these effects are temporary and usually fade within a week as your body recalibrates. To make the transition smoother, it’s best to reduce your intake gradually rather than stopping abruptly — for example, cutting down by one cup every few days or replacing one serving with decaffeinated green tea. This approach helps your system adapt naturally while maintaining your daily routine.

Along with caffeine, green tea contains many other compounds that are not only beneficial for health but can cause harm to your health. Green tea has substances like antioxidants that control oxidant levels in the blood and are useful for health. If not taken properly or without consulting a doctor first, it may harm your health. Such problems caused by tea are explained below:

IMPAIRED IRON ABSORPTION DUE TO GREEN TEA

Green tea contains an antioxidant known as flavonoids that benefits human health in many ways. Food and tea that contain flavonoids when consumed help the body to absorb nonheme iron present in the blood and thus increase the iron level in blood. The nonheme iron is also present in plants like beans, vegetables, and fruit. However, if you drink tea right after the meal, then flavonoids will bond with iron resent in the meal, and these bonds body cannot absorb or use. 

It is advised not to drink green tea with a meal because it will lead to less absorption of iron from your food into the blood and result in iron deficiency. If you want to drink tea, then at least wait 45 minutes or an hour after eating a meal.

Moreover, squeeze a little lemon to your green tea because it will help in the prevention of the flavonoids binding to the iron in your diet. So, if you take green tea with a meal, then the best way is to squeeze a lemon into your cup and have the best health benefit.

Another important point to note is that green tea’s natural compounds, while beneficial, can interfere with the absorption of certain nutrients if not consumed properly. The tannins and polyphenols found in green tea are powerful antioxidants, but they also bind to minerals like iron, zinc, and calcium, making them harder for the body to absorb. Over time, this can lead to mild deficiencies, especially in individuals who already have low iron levels or follow a mostly plant-based diet. To minimize this effect, avoid pairing green tea with iron-rich meals and instead enjoy it between meals or with a slice of lemon, as vitamin C enhances iron absorption. This simple habit allows you to continue enjoying green tea’s many health benefits without compromising your body’s ability to take in essential nutrients.

THE NOT-SO-SWEET RESULTS OF DRINKING SWEET TEA

The best way to drink tea is self brewed with little sugar added. However, If you buy green tea in an already made bottle from a store or add a large amount of sugar or honey, then it is not healthy for your body. In this way, you are adding extra calories to your daily calorie intake, and that will lead you to gain extra weight.

Plain green tea from a teabag or other source is calorie-free and beneficial. However, bottled green tea is sweetened with an excess amount of sugar and can cause health problems such as obesity and diabetes.

Many people don’t realize that store-bought or café-style green teas often contain more sugar than a can of soda. These added sweeteners can easily turn a healthy drink into a hidden source of empty calories. Regularly consuming sugary green tea not only negates its antioxidant benefits but also contributes to blood sugar spikes, insulin resistance, and long-term metabolic issues. Even honey, though natural, adds significant calories when used in large amounts. To enjoy green tea in its healthiest form, brew it yourself using loose leaves or tea bags, and if you prefer a little sweetness, try adding a small amount of stevia or a few drops of lemon instead. This way, you can enjoy the refreshing taste and health benefits of green tea without compromising your wellness goals.

DRINKING GREEN TEA DURING PREGNANCY COULD HARM YOUR BABY

Among many other ingredients, green tea also has tannies, which is not beneficial for pregnant women. Drinking green tea for more than three cups a day affects the baby’s growth and prevents the absorption of folic acid.

Folic acid is an important nutrient during pregnancy and is advised to increase its intake because it helps in protecting against birth defects. According to studies, folic acid supplementation lowers the risk by 70% of spina bifida and other neural conditions.

Lastly, if you are pregnant, then it is advised to limit your intake of green tea to a minimum or avoid it altogether. Fewer nutrients in the body lead to complications during delivery and may cause after effect.

During pregnancy, the body undergoes major hormonal and nutritional changes, making it especially sensitive to caffeine and tannins found in green tea. These compounds can interfere with the absorption of folic acid — a crucial nutrient responsible for supporting the baby’s brain and spinal cord development. Even moderate caffeine intake has been linked to low birth weight or sleep disturbances in newborns when consumed excessively. While one or two mild cups a day may be safe for most women, drinking several cups or concentrated green tea extracts can raise risks over time. Expectant mothers should also remember that green tea supplements often contain higher caffeine levels than brewed tea. To stay on the safe side, it’s best to consult your healthcare provider before including green tea in your daily routine and to prioritize a balanced diet rich in folate, iron, and calcium to ensure healthy growth for both mother and baby.

COULD MY GREEN TEA CONSUMPTION CAUSE MEDICAL PROBLEMS?

Generally, green tea is beneficial for health, but, as stated earlier, the excess is always bad for health. Same way, drinking green tea too much will only worsen the already existed medical conditions. If you have issues like anxiety, diarrhea, and such, then it will increase the level and amount and will leave you sicker.

Moreover, people possessing medical conditions mentioned below should not consume green tea at the risk of making it worse. But if you like to drink, then consult your doctor before drinking it to make sure the small amount is suitable for your body. The health conditions include:

• Bleeding disorders
• Anemia
• Glaucoma
• Heart conditions
• Bleeding disorders
• Any liver condition
• Anxiety
• Diarrhea and other gastric disorders
• Depression

To conclude, green tea has many health benefits but can also damage health if you overindulge and drink in excess quantity. Also, if you have a caffeine sensitivity, then cut down your intake and, most importantly, consult your doctor before continuing your consumption of green tea.

If you have ever thought that Green Tea is an “acquired taste” or that it is “too bitter” to enjoy, we’re here to change your mind! We want everyone to experience the health benefits of Green Tea and show you that this can be an amazing, refreshing, and delicious drink when made correctly. With just a few tips on how to brew this powerful leaf, we can change your mind about the taste and enjoyment of drinking Green Tea.

Despite the harmful effects, you should not miss out on the health benefits of green tea.

Green tea helps regulate weight

One of the significant benefits of drinking green tea and popular reasons is to lose extra fat. Green tea increases metabolism, and as a result, more energy and less fat is stored in the body and is especially melt the fat from the abdominal area. Because of the fat burning process, you gain more energy, and your body stays active and fresh throughout the day.

Green tea increases brain function

Green tea has a key ingredient, caffeine, which is also known as a stimulant because it keeps the brain active. It is also present in coffee, but in tea, it has less amount and thus does not cause jittery, which often happens due to over drinking of caffeine. Caffeine has a significant effect on the brain and improves functions like mood, reaction time, alertness, and memory.

Besides caffeine, green tea also has L-theanine, which helps in increasing the activity of neurotransmitters responsible for anti-anxiety effects and thus keeps you relax and calm. The combination of both ingredients can have a noticeable impact on your brain and its functions. It is important to note that these are in very low quantity and gives you much mild and stable energy buzz. Many prefer tea over coffee because it keeps them active and productive the whole day.

Moreover, it has other bioactive compounds too that help older adults to reduce the aging brain. It lowers the risk of dementia and other neurodegenerative diseases.

Green tea reduces the risk of heart disease.

It helps in lowering the risk of cardiovascular diseases that leads to death worldwide. The studies have shown that green tea improves many factors that reduce the risk, such as lowering the cholesterol level, increasing the antioxidant capacity in the blood, etc. people who drink green tea have nearly 31%less chances of dying from heart disease or stroke.

Green tea improves health in many ways and helps fight diseases

The green tea comes with enriching compounds that benefit your health in many ways. It contains polyphenols, a natural ingredient that has many positive effects on health and reduces the risk of inflammation and cancer.

Catechins are natural oxidants that protect the cell from damage by reducing the radicals that cause the damage and thus protecting the body from disease and early aging. Also, it is the most important that gives green tea its medicinal properties. Lastly, it also contains minerals that help your body in many ways and make you healthier.

How Many Times A Day Do You Drink Tea?
I was curious, so I asked this question to everyone at Private FB Group, Green Tea Club.  Here is the answer from the poll. If you want to join us and have tea conversation, please click here to join Private FB Group, Green Tea Club.

Conclusion

Green tea remains one of the most beneficial beverages when consumed in moderation, offering countless advantages for the mind and body. However, just like any other health-boosting drink, overconsumption can reverse its positive effects and lead to discomfort or even health complications. Understanding your body’s limits, staying aware of your caffeine intake, and timing your tea consumption wisely are key to enjoying green tea safely. When balanced correctly, it can be a soothing, revitalizing, and truly health-enhancing part of your daily routine — not a risk to your well-being.