N-acetyl cysteine (NAC) is a stable form of the non-essential amino acid cysteine. It is a sulfur-containing amino acid that acts as a stabilizer for the formation of protein structures, and is also necessary for the formation of glutathione.* Selenium is an essential trace mineral that facilitates the production of several important enzymes.* N-acetyl cysteine (NAC) is a stable form of the non-essential amino acid cysteine. It is a sulfur-containing amino acid that acts as a stabilizer for the formation of protein structures, and is also necessary for the formation of glutathione. Molybdenum and selenium are essential trace minerals that facilitate the production of several important enzymes.N-acetyl cysteine (NAC) is a stable form of the non-essential amino acid cysteine. It is a sulfur-containing amino acid that acts as a stabilizer for the formation of protein structures, and is also necessary for the formation of glutathione. Molybdenum and selenium are essential trace minerals that facilitate the production of several important enzymes.Selenium (from L-Selenomethionine) 25 mcg, Molybdenum (from Sodium Molybdate), N-Acetyl Cysteine (NAC) 600 mg Other Ingredients: Hypromellose (cellulose capsule), Stearic Acid (vegetable source) and Citric Acid.