Guna brain specifically dosed active ingredients: NAC (N   ACETYLCYSTEINE) : Precursor of Glutathione. Together with Selenium, it makes up the enzyme glutathione peroxidase, a powerful intracellular antioxidant, which also exerts an important chelating action on toxic metals. Dietary supplementation of Selenium and Manganese is very important as they help protect cells from oxidative stress. Green tea leaf extract is a tonic, useful in cases of physical and mental fatigue. Moreover, it also has an antioxidant effect. Indian Ginseng , is a tonic-adaptogen, useful in cases of physical and mental fatigue.