NAC N Acetyl L Cysteine Copper Peptides Serum (GHK Cu) 0.10% Pure Formula Asterwood 2 weeks in on GHK Cu and the glow is REAL. Brighter complexion More even skin tone Less breakouts Softer fine lines Thicker, fuller hair This is just Engineered Cellular Resistance: The Science of Momentous Longevity NAcetylcysteine (NAC) is More Than Just an Antidote. NAC replenishes glutathione (GSH), breaks mucus disulfide bonds, and modulates glutamate. That's why it works in the liver, lungs, and brain. Owais