HEALTHVIT FITNESS N - ACETYL CYSTEINE N-Acetyl-Cysteine (NAC) is a more stable form of the amino acid L-Cysteine and is the most effective way to boost Glutathione levels in the body. NAC is a more stable form of L-Cysteine because it has an acetyl group (CH3C0) attached. NAC has all the properties of L-Cysteine but is more water soluble and said to be more bio-available than L-Cysteine. NAC naturally stimulates glutathione, an antioxidant enzyme. People who have autoimmune problems are often deficient in glutathione. NAC has been used to raise immunity to the flu, and also to treat chronic respiratory problems. A recent study was conducted in which most of the subjects were over 65. Results showed that only 29 percent of those taking NAC developed flu symptoms, compared to 51 percent of those who took the placebo. NAC makes up 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 defenses and enhance cellular health and longevity. These qualities make NAC especially beneficial for active people, the elderly and those exposed to polluted environments.