The BLU-U is a unique blue light that kills the P. acnes bacteria in your skin. Treatments are simple - you sit with your face close to the light for a short time at a schedule set up by your skin care professional, approximately a 17-20 minute session about once or twice per week. The treatments may go on for five weeks or so. It's safe, it's not hot, it's not painful. After some weeks, the blue light can help control your acne.