Understanding Hair Removal Hair grows in cycles, and many factors influence its growth. Age, ethnicity, medications, hormone levels, and even body site all influence the length, coarseness, and colour of body hair. How much hair you have depends on how many hairs are in their active growth cycle and how long that cycle lasts. Hair revolves through three phases of growth: anagen, catagen, and telogen. Anagen is the active growing phase in which the hair bulb is intact. The hair grows in both directions, upward and downward. Early anagen is when the bulb is closest to the surface of the skin, and contains an abundance of melanin (pigment) allowing for the most effective treatment. Catagen is a brief intermediate phase between anagen and telogen. It is the regression phase when the lower part of the hair stops growing but is not shed, and the body absorbs the lower third of the follicle. Telogen is the resting phase. The hair bulb is no longer present, and is now a club hair, which will fall out, or be pushed out of the follicle by a new anagen growing hair. Laser treatment for hair removal is effective on hairs that are in their growth or anagen phase. Hairs that continue to grow after a treatment may be in their telogen phase (not growing) or the laser may not have penetrated well enough with enough energy. To help prevent having undisturbed hair follicles, your laser specialist's goal is to start at a low energy setting and increase it until they have established the highest energy level possible without causing injury or unbearable discomfort to the individual. In skin types 5 and 6, medium or high energy levels are never used as it may cause trauma to the skin and result in possible scarring and hyper/hypopigmentation changes, therefore it will take many more treatments for these skin types to achieve their desired results. Your Body's Response Some areas of the body may respond to treatments better than others. This is because most areas have different telogen (resting) durations and amounts of hair in its telogen stage. For example, you can have your upper lip and sideburns treated at the same time. Most of the hair on your upper lip does not grow back, but you do not notice much difference on your sideburns. This is because only 10% of the hair on your sideburns may have been in its growth stage (anagen) and about 65% of the hair on your upper lip was in its growth stage. It is important to understand that laser hair removal is most successful when done in multiple treatments. One treatment will not be near enough unless you only desire a thinning effect. With each treatment you should notice that more hair does not grow back, and we recommend at least 4-6 treatments for facial areas and 3-5 treatments on body areas. These are average results for most clients. You should also be aware that the hair may grow back in the future if you have any changes in your hormones especially for areas treated on the face. The hair on your body at any given time may be in anagen of about 20% average. The other 80% may either be in catagen, or telogen. This is why you only get about 20% permanent reduction per session, and why multiple sessions are needed. Below we have listed a Richards-Merhag Chart for the cycles of hair growth and their respective duration, density and depth.     Telogen Anagen Telogen Anagen Density Follicle   % % duration duration hair/cm2 depth Scalp 13% 85% 3-4 months 2-6 years 350 3 - 5 mm Eyebrow 90% 10% 3 months 4-8 weeks - 2 - 2.5 mm Ear 85% 15% 3 months       Cheeks 30-35% 50-70% 1 year - 880 2 - 4 mm Beard–chin 20% 70% 10 weeks 16 weeks 500 2 - 4 mm Upper Lip 35% 65% 6 weeks 6 weeks 500 1 - 2.5 mm Axillae 70% 30% 3 months 4 months 65 3.5 - 4.5 mm Trunk NA NA - - 70 2 – 4.5 mm Bikini 70% 30% 3 months 4 months 70 3 – 5.5 mm Arm 80% 20% 18 weeks 13 weeks 80 2 – 4.5 mm Leg 80% 20% 24 weeks 16 weeks 60 2.5 – 4 mm Breast 70% 30% - - 65 3 – 4.5 mm