What is the bad affect of using doxycycline to treat acne?

It's usually okay: You may get some diarrhea from it, and if you're a female, you may get a candida infection. If this happens, stop it. It can make you sensitive to sunlight. Don't ever use an antibiotic as sole therapy for acne, but in conjunction with benzoyl peroxide. Milk, antacids, and iron deactivate tetracyclines if you take them together.