The mechanism of action of N acetylcysteine (NAC): The emerging role of H2S and sulfane sulfur species ScienceDirect 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 DID YOU KNOW NAC is a precursor to glutathione, the master antioxidant? This means it boosts your body's natural detox abilities, combats oxidative stress, and promotes overall immune health. Support your body Natural Factors N Acetyl L Cysteine 600 mg, 60 Capsules Highland Health Foods