NAC SUSTAIN is in our SUSTAIN bilayer Quick Release/Sustained Release format of N-ACETYL-L-CYSTEINE (NAC); a powerful antioxidant amino acid and a precursor to the critical antioxidant glutathione.* Glutathione exerts a variety of protective effects; including detoxification and intracellular defense against oxidativestress.* Substances known to reduce glutathione status are acetaminophen and alcohol.* The advanced bilayer SUSTAIN tablets combine 1/3 Quick Release and 2/3 Sustained Release formats to both immediately raise and to maintain blood levels over a longer period of time.* NAC SUSTAIN releases in the small intestine over a 4 hour period; compared to the 1.5 hour biological half-life of NAC in the bloodstream.* Protected by U.S. Patent # 6;623;754. Keep out of the reach of children.