Hi I just wanted to chime in here and say that we've recently purchased a light therapy machine for our daughter who had terrible Acne and it's done wonders for her. Her Acne would flair around her time of month which was so bad at times that she didn't even want to go outside anymore. However, since she's been using her light therapy, the worst she's ever seen was a breakout in redness during her menstrual cycle which would last only a few days.
One other thing that she discovered through all of this is that many of the products she was using were actually making things worst by putting the skins oil levels off balance. She's since stopped all other treatments and has been washing her face only once per day(in the morning) which has proven to work best in her case.