Sulfamethoxazole / trimethoprim
"I've had acne for years... this is the only medicine that works.  Weird thing is, new dermatologist tried to talk me out of it, but wouldn't tell me why.  I basically told her that if she didn't want to prescribe it, I would just go back to the doctor who did.  At 41 years old, I know what works for me. Another interesting side effect - I used to get ear infections and strep throat on a regular basis until starting this... haven't had either in years !"