acne
"I had been having bad breakouts for about a year but after 2 months on doxycycline my skin was completely clear! i took it for 6 months. although the side effects were not good. i had been having bad headaches for about 5 moths (same timeframe as i had been taking doxycycline for) and finally went to the doctor to find out if doxycycline had affected the fluid in my brain causing swelling of the optic nerve. I was told this was a very very rare side effect of the doxycycline. did wonders for my skin tho!"