"i&#039;ve been on doxycycline 3 weeks now, i&#039;ve had cystic acne for 3 years now i have it under control with benzoyl peroxide.  i still have a few cysts here and there so i decided to try the doxy to get rid of all of it once and for all, i&#039;ve noticed my overall skin more glowy and healthier looking and i haven&#039;t had 1 cyst since getting on it but i have had several small zits in places i never usually get them like my forehead. i think that&#039;s the medicine pushing out all the bad stuff hopefully it will be 100% by the 1 month mark when i go back to the derm (i&#039;m also using retin-a topical at night) doxy never effected my stomach or gave me any type of side effect at all."