Under the influence of the laser beam, passing along the trunk hair, cell heating occurs, containing melanin, and the subsequent destruction of the hair follicle. Skin is not damaged, a little warm up and cool down quickly. Laser hair removal allows you to remove only the hairs, which had grown to 3-5 mm and are visible on the surface, i.e, They are in the active growth phase (anagen). But there is always a "replacement" or dormant hair follicles, which come in the anagen phase after procedures, therefore, for the complete removal of unwanted hair requires multiple sessions.
As each procedure, this method with its use immediately revealed the pros and cons, to be aware of before session. The main disadvantage of laser hair removal is a mandatory contrast hair and skin, to melanin, contained in the hair, and not in the skin, absorbs laser radiation.
So, eg, in the case of dark hair on dark skin or light (red) hair on light skin is almost the desired effect is not achieved. For effect requires dark (dark brown) hair on light skin, then the laser beam is absorbed by the hair is. But today it is possible to solve these problems, for this you just need to choose the desired type of laser exposure.
The relative disadvantage is the cost of the procedure, but when you consider, the effect of laser hair removal - is the complete lack of hair, the negative can seem a big plus.