Glutathione is a key component of the antioxidant system which protects the body from free radicals at the cellular level. Reduced glutathione is involved in the synthesis and repair of DNA, and enhances the antioxidant activity of vitamin C, the transport of amino acids, and the detoxification of harmful compounds. In addition, an intracellular abundance of reduced glutathione, as compared to oxidized glutathione, helps ensure healthy cell function. It is especially important for liver function.