Why does laser hair removal require several sessions?

Many people wonder why laser hair removal, on average, takes 6 to 12 treatments, instead of just one visit. The answer lies in the hair growth cycle. How does hair grow? What happens during this cycle? Here are the basics of the hair growth cycle and how it relates to laser hair removal.

The Hair Growth Cycle

Hair goes through three separate stages as it grows. The growth phase (anagen) is where your hair is actually growing. at any given time, most of the hair on your body is in this phase.

The transitional phase (catagen) is when the follicle rests, and cuts off the hair from its blood supply.

The resting phase (telogen) is when the follicle is dormant. The hair is in place, but not growing any longer. At the end of the cycle, the growth phase begins again, shedding the old shaft of hair and beginning a new one.

When you shave off a hair, you simply shorten the shaft but it keeps growing below the surface and quickly reappears. When you use laser treatment, it targets the hair follicle itself, so that it will no longer produce a shaft of hair.

Laser treatments specifically disable hair follicles that are in the catagen phase of the cycle. Since not all of your hair is in the same growth stage at the same time, each treatment will address the portion of your hair that is in that stage at that time. By scheduling a series of treatments four to eight weeks apart, you can treat all of your hair.