Be Cautious Before You Drink Green Tea: Here are 5 Possible Side Effects


Too much of anything is never good for you, even if it is the healthiest beverage on the planet. People of China and Japan may tell you otherwise- they drink multiple cups of green tea daily-but there’s no harm in knowing about the potential side effects, is there?

These side effects are caused as a result of toxicity from high doses of the most potent catechin found in green tea called epigallocatechin gallate or EGCG. Green tea is packed with this powerful antioxidant that has been linked to several health benefits. These include cancer prevention, skin rejuvenation, lower risk of heart and gum diseases and diabetes, lower cholesterol and increased concentration.

The side effects of green tea, if any, can occur if you decide to chug one too many cups of this popular beverage.

Side effects from caffeine

Green teas contain caffeine in varying amounts. They are a great alternative to coffee but are not free from caffeine. An 8 fl. oz. of green tea can contain anywhere from 24-25 mg of caffeine.

So, if you drink green tea excessively, then you might experience side effects due to over consumption of caffeine. These side effects can include:

  • Insomnia
  • Nervousness
  • Hyperactivity
  • Increased heartbeat
  • Muscle tremors
  • Irritability
  • Headaches

Green tea can cause an upset stomach

Green teas contain tannins, the high dose of which can cause your tummy to be unwell. Drinking more than 5 cups of green tea can cause vomiting, diarrhea, nausea and constipation in some. It is more likely when you drink green tea on an empty stomach.

Green tea might reduce iron absorption

A 2001 research suggests that the antioxidants in green tea can decrease the absorption of dietary iron.[1] However, there are a couple of studies that contradict this. According to these researches, there is no effect of green tea in iron absorption.[2,3]

Green tea may not be good during pregnancy

This is because of its caffeine content. To-be mothers are usually advised to limit their daily caffeine intake to not more than 200mg per day.

Another important reason to limit green tea consumption is because it reduces the absorption of folic acid.[4]Folic acid plays a significant role in the neural tube development of the embryo.

Green tea interacts with medications

If you are under medication, then it is best that you consult your physician first before drinking green tea or taking green tea supplements. Green tea is known to inhibit the effects of drugs like adenosine, benzodiazepines, blood thinners and clozapine.[5]

Ranjit Bhatta
Ranjit is a huge natural and organic product lover and tries to incorporate them in his daily life. His goal is to share his success with nature while keeping up with the modern needs. He is a big fan of Ayurveda, specially Shilajit - an Ayurvedic panacea. Besides nature, he's an avid massage lover specializing in massage chairs.