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 Amazon.com: Advanced Complex NAC Supplement (N Acetyl L Cysteine) 600mg with L Glutathione 500mg and Milk Thistle Extract Potent Antioxidant Immune Function Support Respiratory Health Promotes Liver Kidney Detox : Health & Household Pure Encapsulations NAC (N Acetyl l Cysteine) 600 mg. Towncrest Pharmacy 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