Overview NAC is a precursor to glutathione, a critical antioxidant scientifically proven to scavenge free radicals. NAC has the unique ability to maintain healthy lung tissue, support the body's natural defences and enhance cellular health and longevity. These qualities make NAC especially beneficial for active people, the elderly and those exposed to polluted environments. Medicinal Ingredients Each Capsule Contains: N-Acetyl-L-Cysteine (NAC) 500 mg Non-Medicinal Ingredients Rice starch, vegetarian capsule (carbohydrate gum [cellulose], purified water), vegetable grade magnesium stearate (lubricant). Advanced Info N'Acetyl Cysteine (NAC) 500 mg capsules contain a highly stable form of cysteine, an important sulfur-containing amino acid. The NAC-Glutathione Connection: Glutathione is vital to the body's antioxidant defense system. Adequate levels of glutathione may protect against atherosclerosis, cataracts, macular degeneration and some liver diseases. Although some supplements contain glutathione, it is preferable to take a precursor, such as NAC, to raise glutathione levels, because most supplemental glutathione is hydrolyzed in the gastrointestinal tract before being absorbed. NAC increases tissue levels of glutathione and is less expensive.