Isotretinoin
"When I was a teenager I suffered from terrible acne and scars.  I was put on Accutane and while I was quite moody, it was totally worth it because when I was done my skin was flawless.  I was never happier.  My skin stayed this way for years until my doctor informed me that the hormone changes during pregnancy were probably the cause for my acne resurfacing.  My birth control was helping. It wasn't until I got a blood clot in my chest and was told I could never take birth control again that it got worse.  I never realized how much the birth control was helping.  My skin got so bad I never wanted to leave the house.  I am going back on Accutane in a few days and praying I get the same results I did 15 years ago."