Green tea leaf extract packs a standardized dose of catechins (especially EGCG) and caffeine into a capsule or tablet. It delivers antioxidants in a stronger concentration than a brewed cup of tea.
The natural caffeine and L-theanine sharpen mental focus and keep energy steady, usually without the jitters. Catechins contribute to heart and immune health through their antioxidant effects. Some people also take the extract to help the body process blood sugar within its normal range.
Take green tea extract once or twice daily with food to avoid an upset stomach. Most people prefer morning or early afternoon doses so the caffeine does not disturb sleep.
Large EGCG doses have been associated with liver concerns in rare cases. Caffeine can cause insomnia or nervousness. The extract may interfere with blood thinning medications. Talk to a health professional before use.