As a precursor to make glutathione, NAC has been used for decades both as an acute medication and as an over the counter supplement. Recently, the line between medication and supplement has been Amazon.com: GlyNAC ET NAC Supplement N Acetyl Cysteine Ethyl Ester 20x More Bioavailable Glycine & N Acetylcysteine Ethyl Ester Anti Aging Supplement, Boost Glutathione, 60 Capsules Nutri 3rd Party Tested : numbuzin No. 5+ Vitamin Glutathione Dark Spot Laser Cream Why We Love It Apply no.5 product first and then apply a thick layer of no.5 cream at last to provide 217% NAC N Acetyl Cysteine + Glutathione 2028mg Antioxidant Supplement eBay All About NAC (N acetylcysteine): What it is and what benefits it has Zenement