Adapalene
"I've been using this gel for probably about 2 or 3 years now. I started getting acne in around 6th grade where as I didn't start my period until 9th grade. I've never had SEVERE acne, there's just always been at least a couple zits on my face for as long as I can remember. I had no significant peeling or dryness when I started using differin, and I also had no immediate results. Slowly over time, however, my acne is becoming less severe and less often. Maybe it's because of the differin, maybe it's because I'm growing out of it. I did stop using it last summer as a test and my skin got worse and worse for the entire month I stopped using it and it took a solid 3-4 months after I started using it again for my skin to return back to normal."