"i have been on doxycycline for 7 and a half weeks.  it says it takes 6-8 weeks to work and that is absolutely true.  i still have acne right now but its definitely clearing up in this week.  i made the mistake of touching my face a lot and picking at my acne which will not help it clear up.  i am taking one tablet of doxycycline 100mg a day with clearasil foam wash twice a day with aczone in the morning and epiduo at night.  just be patient and it will work in 6-8 weeks."