NAC Detox Regulators with Seleno Excell(R) from Doctor s Best(R) is a combination formula of NAC (N-acetyl cysteine) selenium and molybdenum. This specialized blend promotes production of glutathione--the master antioxidant--in the brain liver and other organs. NAC boosts glutathione production while selenium and molybdenum assist proper glutathione function in the body. Optimal glutathione levels support energy production detoxification and more.