I bought this serum mainly to fade my acne scars, and although I haven't seen a great difference on that, it has evened out my skin tone. My skin looks more healthy and fresh after using it. Since I read that this has mildy exfoliant properties, I only use it every two days at night, after a low PH cleanser and leave it work on my face for 20-30 minutes. I keep it refrigerated and inside its box, so no oxidation has happened to my serum.