N acetylcysteine (NAC) is a supplement I frequently recommend to clients most commonly for conditions such as endometriosis or as part of post concussion protocols. Some of you might also recognise NAC Amazon.com: Asterwood Copper Peptides Serum for Face with GHK Cu Peptide and Hyaluronic Acid Anti Aging Facial Serum 1 Fl Oz : Beauty & Personal Care Copper Peptides Serum (GHK Cu) 0.10% Pure Formula Asterwood Active just means the serum contains a functional, lab verified concentration of real GHK Cu copper peptide not just colour or trace copper. Our formula includes 300mg of pure GHK Cu (1% concentration) in Vitabright NAC Supplement 600mg x180 Capsules Pure NAC Acetylcysteine for Glutathione Detox Post Workout Gym Supplements