Jarrow Formulas has released N-A-C Sustain, with 500mg of N-Acetyl-L-Cysteine in a vegetarian capsule form. The supplement is an antioxidant amino acid, and supplies L-Cysteine, which acts as an antioxidant itself or as precursor to glutathione, the company says. It is meant to support glutathione production in the brain, liver, and other organs while also supporting immune function.