Tretinoin
"I've had mild acne ever since I was 11 but it started to get MUCH MUCH worse when I hit 15. So at 15 I went to a dermatologist and was prescribed tretion 0.025 cream, I didn't have a Initial purge phase, but I did have really dry/peeling skin for the first month. I was using it for about 6 months, it worked miracles for my skin! it took about two months to really kick in. But then my tube of the cream got thrown away by accident and I was off of it for three weeks. My skin got worse than it initially was within that time, two months after that and I was seeing no results so I went back to my derm and got prescribed the 00.5 cream. I've been on it for two months now and my skin is mainly clear again. This cream does work. Give it time."