Doxycycline
"It started to clear up my acne after a few months of taking it, but the side effects were awful. I felt nauseous instantly afterwards and then was also sometimes sick, I couldn't sit or lie down for at least an hour afterwards and if I did I was guaranteed to be sick. I also had to make sure that I ate beforehand and didn't take the medication on an empty stomach because that would also cause sickness. The nausea was the worst part because I had to sit for half an hour feeling sick before I actually was which made it even worse. I eventually stopped taking it after about a year because my acne had completely cleared up, but then 6 months later it came back...only a temporary fix for me and the effects of it almost make it pointless"