At first I didn't notice any difference with this serum. a few months later my skin was rough, zit-prone and red. Turns out one of the reasons was this serum. I didn't know when I bought this, but after doing some research, despite what the beauty industry says, gold is actually a really bad skincare ingredient. if it's fine enough like in this serum, it gets absorbed into your skin and blocks the little pathways in your skin that deliver nutrients and other stuff. after I stopped using gold in my skincare my face dramatically improved. Not so much a problem with this particular product as with gold in general.