Doxycycline
"I'm a 19 year old female and my skin was perfect until I turned about 17. Then it still wasn't too bad, a couple of pimples every now and then. It started to get worse over the last couple of months, mild acne, so I was prescribed doxycycline 50mg once daily. I have been on it for three weeks now and my skin is worse than it has ever been. My face is covered in huge red sore bumps and I have scarring everywhere. I wake up with at least three new pimples a day. I am about to give up on this stuff because it has made my skin 10 times worse than it ever was. I have heard it gets worse before it gets better but I've read it usually only takes 2-3 weeks to see improvement but it doesn't look like it will be getting better anytime soon."