Hair grows in three different main stages: Anagen, Catagen, and Telogen. Only hair that is in the Anagen stage of growth, known as the first stage, can be successfully used for hair reduction. Hence there are multiple sittings to this procedure. Pulsed laser causes heat strong enough to damage hair shaft and follicle and thereby obliterates its ability to produce new hair. Treatment duration between each appointment can vary from 30 days or more depending on your hair growth.