Green tea is one of the most commonly consumed teas in the world.Green tea extract is its concentrated form, with just one capsule containing the same amount of active ingredients as an average cup of green tea.Like green tea, green tea extract is a great source of antioxidants. These have been credited with a range of health benefits - from promoting heart, liver, and brain health to improving your skin and even reducing the risk of cancer. What's more, many studies have looked at the ability of green tea extract to aid weight loss. In fact, many weight loss products list it as a key ingredient.