Laser hair removal is very successful. The length of laser hair removal treatment depends on each person's makeup and body chemistry. But once hair follicles have been treated and destroyed, they can no longer produce hair. Hair that is entering the anagen phase (growth phase) after laser treatment will need to be treated again.
The light energy passes harmlessly through the skin, but is absorbed by the pigment in the hair follicle and hair shaft. By absorbing this laser energy, the hair follicles are disabled, impairing their ability to grow. The laser is effective on hair follicles in the active growth phase (anagen).