"i was told by my doctor to take the doxycycline 100mg once a day for 3 months. so far it has been 3 weeks and i think my acne is getting worst. the first week my acne seemed to be improving. that was until the 2nd week it started getting worst. i&#039;m starting to think it might be my period causing me to break out again. so i&#039;m hoping i will see an improvement when its over. i have had no bad side effects which is great. after reading positive feedback on this i am really hoping to see a huge difference!! be patient"