Laser or light energy is selectively absorbed by the melanin in hair follicles and converted to heat, diffusing to and injuring stem cells in the bulb and bulge. Effective hair reduction can only be achieved during the active growth phase and hair reduction is considered permanent when a significant amount of hair does not return for a period of time longer than the complete growth cycle. After a series of treatments, most hair is permanently removed. However, if hair does regrow it will be finer and lighter than before.
