Laser hair removal works by targeting the melanin (pigment) in hair follicles. Hair grows from follicles beneath the skin, and the only “living” part of the hair is the bulb/root, which produces new hair. The laser is most effective when hair is in the anagen (growth) phase because the hair is still connected to the follicle and blood supply, allowing the heat from the laser to destroy the follicle and reduce regrowth. During the catagen (transition) phase, the hair begins to detach, making the treatment less effective, while in the telogen (resting) phase the hair is dormant and laser treatment has little to no effect.

Because hairs are always in different stages of growth, multiple treatments are needed to effectively reduce unwanted hair. Regular sessions, usually spaced about two months apart, are recommended so more hairs can be treated during the active growth phase. Most clients need at least three sessions to achieve significant results, with reductions of up to 80–92% possible. Since the body can regenerate some follicles over time, occasional maintenance treatments once or twice a year may be needed to keep the skin smooth.