acne
"I'm 27 and I just started taking doxycycline 2x a day 100mg. I saw my skin clearing up or at least no new pimples since day 1! I also use tretinoin cream at night and benzaclin/clindamycin in the morning. I had an upset stomach so far only for one day but the past two days I've been dealing with a bad headache. I'm hoping it'll go away soon. Other than that, this medicine works great on me!"