NAC (N Acetyl Cysteine) Antioxidant Support for Glutathione Production 600 MG (120 Capsules) by Megafood at the Vitamin Shoppe What is NAC (N Acetyl L Cysteine)?, NAC is a derivative of the amino acid L Cysteine, designed to be more stable and bioavailable than regular cysteine on its own., Lets break it down:, Cysteine They dont call it the Hot Girl Peptide for nothing! , Ive been obsessed with GHK Cu lately because its the only thing that actually cleared my acne redness AND fixed my receding hairline. Celluglow Liposomal Glutathione + NAC, ALA for Skin Brightening