Nutrition and Supplements Special supplements Jarrow Formulas N-A-C 500 mg x 60 Capsules N-Acetyl-L-Cysteine (NAC) Sustain is a powerful antioxidant amino acid and a precursor in the body to the critical antioxidant glutathione. N-Acetyl-L-Cysteine supplies readily available L-cysteine, which acts as an antioxidant itself or as a precursor to glutathione. Glutathione is one of the bodys most important and abundant antioxidant and detoxification agents. * Glutathione is essential for the immune systems proper functioning, is vital in maintaining healthy tissue, and supports liver function. NAC Sustain is formulated with advanced bilayer Sustain tablets that combine 1/3 Quick Release and 2/3 Sustained Release formats. How to Use: Adults take 1 tablet 1 or 2 times per day or as directed by your qualified healthcare professional.