Green Tea Side Effects - What Substances Are In Green Tea?

Health TV shows and magazines have been advertising green tea extract as an effective supplement for weight loss. With the increasing interest of tea, many are concerned about the safeness of the supplement. A majority of the media promoting the benefits of tea are usually not explaining enough of the side effects. Thoroughly knowing the potential negative effects is important to be able to take benefits without having harmful results.

Just like many dietary supplements or medicines, the amount has an important role with regards to negative effects. If consumed without care, even the most natural supplement triggers unexpected reactions. Same logic applies here. What exactly is the safe amount of tea?

The most active substances of tea are caffeine and catechin. Both help with using fat as the source to make heat which is known as thermogenesis. This process in return increases metabolic rate. Accelerated metabolism burns body fat much faster in the body.


There were countless scientific studies on caffeine and how it affects human body. Many health specialists are saying commonly above 500mg of caffeine a day is too much. It could be harmful resulting in unwanted effects such as insomnia, nervousness, restlessness, irritability, stomach upset, fast heartbeat and muscle tremors. Health experts furthermore agree that sensitivity to caffeine ranges by an individual, but 300mg or below is regarded a low risk dosage.

A single cup of tea possesses about 20mg of caffeine. Compare to coffee, it is a small amount. A single cup of coffee possesses about 100mg of caffeine. If tea is the only caffeinated drink taken then it should not be a concern. But if other caffeinated drinks are consumed throughout the day, then it is critical to check the total daily dosage of caffeine.

Researchers carried out laboratory tests regarding dosage. A daily dosage of 800mg of EGCG has been tested successfully and with no uncomfortable side effects. A cup of green tea has about 100mg of EGCG, which is about 8 cups of green tea. A lot of laboratory tests suggest more EGCG means greater fat burning, however some health professionals agree that an excessive amount of one ingredient from herbs could be problematic. It is not easy to make an absolute conclusion based on lab studies, still numerous health experts are claiming 300mg of EGCG is an ideal dosage to take in a day. There have been good clinical outcomes with the amount of 300mg against cancer cells and weight loss.

With the raising curiosity about green tea, even more tests will be conducted. In the meantime, 300mg seems to be a safe dosage for both caffeine and EGCG.