Permanent hair reduction is achieved by using heat to disable the hair follicle and prevent re-growth. The bulb and bulge of the follicle are the areas believed to be responsible for re-growth; these areas are targeted by the Nd:YAG laser and ProWave handpiece. Multiple treatments are required to achieve sufficient reduction in hair growth because each hair goes through 3 growth phases (anagen, catagen and telogen) and only the hair follicle in the anagen growth phase can be disabled. Each hair passes through the growth phases independent of the neighboring hairs so not all hairs will be in the same phase at the same time, thus multiple treatments are required. Treatment Intervals: Treatment Interval recommendations are a general guideline only and are a compilation of intervals used by successful operators. Facial hair: 6-8 week intervals between treatments. Body hair: 8-10 week intervals between treatments Back or Leg hair: 10-12 week intervals between treatments - Hormones, diseases, medication or other factors can affect the treatment outcome. - Treatments that are spaced too close together may appear to be more successful within the first few treatments but a smaller percentage of anagen hair may be available as a target thus more treatment sessions may be required for the desired final outcome. - Patients should be assessed before each treatment to determine treatment intervals and settings. Hair may grow back lighter and finer, so settings may need to be adjusted to target this new hair. - If the patient returns for treatment and there is minimal hair, it may be in a transitional or resting phase. Wait until hair is actively growing to resume treatment cycle. - Facial skin has significantly more hair follicles per cm2 than the body. This is why you can see results within the first three to four treatments with shorter interval times. - When in doubt, it is better to space the treatments farther apart than closer together.