N - Acetyl L - Cysteine ( NAC ) is a precursor to glutathione, the body ' s master antioxidant, known for its role in neutralizing free radicals and supporting immune function. < ul >< li > Potent Antioxidant Power : Lily Green ’ s N - Acetyl L - Cysteine ( NAC ) provides 1200mg per serving, supporting cellular health and enhancing glutathione production.