A laser produces beam of highly concentrated light. The light emitted by the Long Nd:YAG Laser is absorbed by the pigment located in hair follicles. The laser pulses for a fraction of a second, just long enough to vaporize the pigment, disabling several follicles at a time to eliminate or significantly impede the hair re-growth. Know Your Hair Growth Cycle
Every hair goes through 3 cycles of growth. The hair you can see is either in its active anagen growth cycle (still attached to the hair follicle) or in its inactive catagen phase (already separated from the follicle). Inactive hair will fall out on its own as it has completed its growth cycle and already disengaged from the follicle. Beneath the surface of the skin are the dormant hair follicles that have not entered a growth cycle. The laser targets the hair you can see, meaning it will remove both the active and inactive hairs. Hair in an active growth cycle will not grow back as the laser will destroy the hair follicle beneath the skin. Inactive hair will be removed; however, it will grow back as the follicle is still intact. As the hair moves through its cycles, repeated sessions are necessary to treat the follicles when they enter the growth phase.
The number of session depends on various parameters, including the area of the body treated, skin color, coarseness of hair, and gender. Since hair grows in several phases, and laser can only affect the currently actively growing follicles, several sessions are needed to kill hair in all phases of growth.
In general, it is necessary to foresee between 3 - 8 treatment sessions. Coarse dark hair on light skin is easiest to treat. Finer hair and hair on darker skin is harder to treat and may require more treatments. Certain areas (notably men's and women's faces) may require considerably more treatments to achieve desired results.
Usually, treatments are spaced 3-12 weeks apart to start, although the spacing depends upon individual's response to treatment. Instead of following an arbitrary schedule, you should wait until you have experienced shedding of the treated hairs, which should complete in less than a month, and see enough hair come in after the hair-free period to have another treatment. Treatment spacing also depends on area treated as hair cycles vary based on the body part.
A unique advantage of the CoolGlide Laser is the ability to deliver very high power. It can then eliminate resistant individual hairs, including those fine, light brown hairs which cannot be treated with other lasers. It also treats all skin types (I-VI) including tanned skin in the summer.