how long does doxycycline monohydrate take to work?
Like other acne treatments, doxycycline needs some time to start working. Your acne might start improving within 2 weeks, but it can take up to 12 weeks (or 3 months) to see the full benefit of the treatment. You'll know doxycycline is working for you when you see less acne forming and your skin starts to look clearer.