Number of sessions and Intervals between sessions

Number of sessions

Multiple treatments depending on the type of hair and skin color have been shown to provide long-term reduction of hair. Most patients need a minimum of seven treatments. Current parameters differ from device to device but most clinicians recommend waiting from three (or four) to eight weeks depending on the area being treated.

The number of sessions depends on various parameters, including the area of the body treated, skin color, coarseness of hair, reason for hirsutism, and sex. Coarse dark hair on light skin is easiest to treat. Hair on darker skin is harder to treat. Certain areas (notably men's faces) may require considerably more treatments to achieve desired results. In addition, since hair grows in several phases (anagen, telogen, catagen) and laser can only affect the currently active growing follicles (anagen), several sessions are needed to kill hair in all phases of growth.

Laser does not work well on light-colored, red hair, grey hair, white hair and fine and vellus hair ("peachfuzz") of any color.
Intervals between sessions

Usually treatments are spaced three (or four) to eight weeks apart depending on the body area and the hair cycle length for that area. For example, faces usually require more frequent treatments three to four weeks apart, whereas legs require less frequent treatments and patients should be advised to wait six or more weeks..

Typically the shedding of the treated hairs takes about two to three weeks. These hairs should be allowed to fall out on their own and should not be manipulated by the patient.

Other uses

Hair removal lasers are effective treatment for pseudofolliculitis barbae (commonly called ingrown hairs or "shaving bumps"). For darker skin patients with black hair, the long-pulsed Nd:YAG laser with a cooling tip can be safe and effective when used by an experienced practitioner.

They have recently been reported as helpful treatment for pilonidal cysts, since they eliminate the ingrown hairs that produce the troublesome foreign body reactions in this congenital malady.