The combination of a light source, such as IPL or a blue light (Blu U, Clearlight), and 5-ALA, a topical photosensitizer, constitutes photodynamic therapy. This procedure is a highly effective treatment for acne, rosacea and actinic damage (sun damage). PDT can suppress acne for months to years with 2-3 treatments. Photdynamic therapy improves early red acne scarring and achieves results like accutane without the side effects. PDT is considered a method of chemoprevention because pre-cancers are removed and skin cancer may be prevented. Also, rejuvenation of background sundamaged skin occurs and results in clearer, smoother, brighter and more even skin. Because this treatment is so powerful, fewer treatments are required to rejuvenate sundamaged skin when compared to IPL used alone.