"bactrim has been very effective for me, and i&#039;ve taken it on and off for seven years. i have had no serious side effects (at least none which manifested as of now), and the bactrim does a good job of controlling my acne. side effects are a big deal in acne medication (accutane dried my skin and tetracycline caused ear ringing). while i occasionally get a breakout while on bactrim, the severity and frequency of the acne has decreased. on a side note, i&#039;ve found my acne is most well behaved with a low or no dairy diet."