Ive used it for approximately a 5 month stretch, I find that helps to take the inflammation out of existing acne, but I didnt find that it did much to help prevent new ones from forming. I now use it only as a spot treatment, after applying differin, to help take the hurt and swelling out of any actives. Its also pretty good to apply to ones that you feel coming up; Aczone does a good job of holding them at bay