The number of treatment sessions that a person must undergo for complete laser hair removal depends on several factors, but most importantly, it depends on the hair growth cycle. Body hair grows in three stages: the anagen phase, the catagen phase, and the telogen phase, and since each hair follicle is at a different stage of the cycle at any given time, those seeking complete hair removal need to undergo multiple treatments.
During the anagen phase of the hair growth cycle, hair is actively growing.
The next phase is the catagen phase, when hair stops growing and becomes a club hair. A club hair is cut off from the blood supply and the cells that produce hair growth. The entire process takes a few weeks before the hair enters the telogen, or rest, phase, when the hair falls out and the cycle begins all over again. The complete cycle takes roughly eight to 10 weeks, which is why experienced laser clinics recommend that treatments be scheduled at least eight weeks apart.
Additionally, the area of the body being treated may have a longer or shorter growth cycle. For example, facial hair tends to have a shorter growth cycle whereas the legs and back have longer growth cycles. Treatments for the face would be scheduled around eight weeks apart; treatments for the legs and back would be scheduled 10 or 12 weeks apart. It has been estimated that most people require between five and 10 laser hair removal treatments before complete hair removal is achieved, but since everyone’s growth cycle differs, it’s difficult to tell how many sessions a person will require until a licensed medical technician reviews the initial results.