Tretinoin
"I've been using the 0.05 percent (worked my way up from 0.025) for almost 2 years now. I started off with it because my usually very clear skin started developing small spots that just weren't going away. They weren't very visible but I have grown up with people complimenting my skin all the time and to me, the small spots felt like a blow to my self-confidence. My doctor recommended the cream to me. Within 2 weeks of usage , my skin cleared up. There was some peeling but that went away after my skin adjusted to it. Anyway, I continued with the use for almost 2 years now because my skin has never looked this beautiful and glowy as it does now."