N-Acetyl-L-Cysteine, known as "NAC" provides powerful immune support and also packs a powerful anti-toxin potential. Its ability to neutralize cell and DNA damaging free radicals can help slow down what many scientists point to as a key factor in the aging process. N-ACETYL L-CYSTEINE (NAC) or NAC is a more stable form of L-Cysteine because it has an acetyl group (CH3CO) attached. NAC has all the properties of L-Cysteine but is more water soluble and said to be more bioavailable than L-Cysteine. NAC may be the most cost effective way to boost Glutathione levels in the body. Glutathione is a very valuable peptide, but very expensive when bought as a supplement. It is best to use NAC to boost your glutathione levels. NAC has been shown to play a protective role against a variety of toxic hazards such as cigarette smoke, auto exhaust, certain herbicides, and overdoses of acetaminophen. It can also play a beneficial role in prostate and respiratory conditions. For example, NAC has well established antimucolytic (anti-mucous) properties and has been shown to increase mucocilary transport in smokers. As a beneficial glutathione booster, N-Acetyl-L-Cysteine is the supplement of choice. Surprisingly, it is more effective than supplementing with cysteine, methionine, or even glutathione itself! No doubt NAC is the undisputed glutathione precursor. What makes NAC stand out in the crowd of glutathione boosters is the fact that it is a stable amino acid that can retain up to six times the amount of the sulfur and sulfhydryl groups after digestion. Scientists believe that sulfur and sulfur compounds may be central to glutathione and its precursor N-Acetyl-L-Cysteine (NAC).