Natural Factors Green Tea - 300 mg - As antioxidants, green tea catechins scavenge free radicals, prevent free radical damage, and enhance antioxidant defense systems by stimulating antioxidant enzyme activity such as glutathione peroxidase and catalase. Green tea extract also supports healthy weight loss by decreasing the absorption of fat in the digestive tract. It stimulates thermogenesis, where the body turns fat into energy, better than caffeine or ephedrine and without increasing heartrate.