Laser hair removal is a modern new method of removing unwanted hair. A laser produces a beam of highly concentrated light. Different types of lasers produce different colours of light. The colour of light produced by a particular laser and its method of delivery is the key to its ability to damage the hair follicle.
The pigment located in the hair follicles preferentially absorbs the near-infrared laser light emitted by the diode laser system. The laser pulses for a fraction of a second, just long enough to heat up and vaporize the pigment, disabling several follicles at a time to eliminate or substantially impede the hair’s regrowth, while the system’s unique contact-cooling handpiece helps protect the skin by conductive cooling during the laser energy delivery process. In this way, the laser energy is directed to the hair root while protecting and cooling the surrounding skin.
The length of a laser session may be a few minutes to an hour or more, depending on the size of the area being treated. Because the laser tends to treat hair follicles that are in an active growth phase, more than one treatment is required to disable hair follicles that subsequently enter this growth phase.
Each follicle in human skin maintains an independent growth rhythm from the other follicles. At any given time, a proportion of hair follicles are at some point of the anagen (active growth) phase. The remaining follicles are either in the catagen (regression) or telogen (resting) phase.
Anagen Phase – Hair’s active growth phase is called anagen. During anagen, the hair contains an abundunce of melanin and can be effectively treated by the laser.
Catagen Phase – Catagen is the regression phase when the lower part of the hair stops growing but is not shed, and the follicle is reabsorbed. Treatment in this phase is only partially effective.
Telogen Phase – The resting phase is called telogen, during which the old hair falls out in preparation for the development of new hair.
The proportions of hair in the different phases vary with the area of the body, with the scalp having the highest percentage of hairs in the active growth phase. Hairs in the regression and resting phases appear to be less susceptible to the treatment effects of laser light. However, after initial treatment with the laser, the hairs that regrow appear to be synchronized in the early anagen active growth phase, where they are most vulnerable to treatment with laser light. For this reason, repeat treatments should be performed as soon as possible after the hairs begin to regrow.