 The purpose of this research project is to study the effect of non-ablative non-cutting laser therapy, a technique that uses laser energy to try to improve the appearance of the skin. This type of laser treatment creates changes in a layer of the skin called the dermis without causing an open wound in the skin. The use of non-ablative laser therapy, together with application of a photo-sensitizer substance that makes the skin more sensitive to light, may improve the appearance of acne. The idea behind the photo-sensitizer is that it is supposed to make the laser more effective than using just the laser alone. It is not yet clear how much improvement can be seen with these treatments or exactly how the skins response causes these improvements. In this study, we are interested in learning how well such a laser works to improve the symptoms of acne, as well as how much the photo-sensitizer actually enhances the efficacy of the laser. 