acne
"I was using the 0.10% strength which helped greatly with clogged pores, blackheads, small pustules.  However, I also had cystic hormonal acne, which the cream wasn't effective enough for. I took this in conjunction with spironolactone, but eventually had to take accutane.

Downside of this drug: sun-sensitivity, skin peeling, redness 

For the record, it takes weeks to see results, and your acne gets WORSE before it gets better."