Acetyl cysteine (N-acetylcysteine) ek powerful antioxidant hai jo skin ko free radicals se protect karta hai. Ye glutathione ke liye precursor kaam karta hai aur skin conditioning properties deta hai. Melasma, acne aur damaged skin barrier ke liye study mein use hota hai. Thiol-containing compounds se skin ko heal karne mein madad mil sakti hai.