As I mention in my book, N acetyl cysteine (NAC) is not found in food sources, but in the body, it converts into cysteine. NAC acts as a precursor to glutathione, a powerful n acetylcysteine and glutathione relationship Transtympanic injection of a liposomal gel loaded with N acetyl L cysteine: A relevant strategy to prevent damage induced by cochlear implantation in guinea pigs? ScienceDirect NAC and Glycine: The Efficient Way to Raise Glutathione Amazon.com: 1MD Nutrition NAC Supplement N Acetyl Cysteine NAC 600 mg Antioxidant Supports Detox and Glutathione Production N Acetylcysteine Respiratory Supplement for Lung Health 60 Capsules : Health & Household