Excessive hairiness is relatively frequent and is felt by many people to be unaesthetic. Furthermore, the aesthetic standards of our time require that certain parts of the body be perfectly hairless; the use of a razor, an electric appliance or wax enables this objective to be achieved, but only temporarily.
For a hair not to regrow, the area between the hair and the pilar bulb needs to be destroyed. This area is the one that is located most deeply in the skin (between two and seven mm). The light emitted by the laser is absorbed by the melanin, the pigment found inside the hair. The luminous energy captured by the hair is instantaneously converted into thermal energy. The hair is thus brought up to a temperature of about 70 degrees. The hair thus heated will transmit its heat to the structures that surround it.
Thus, if the hair is well implanted at the bottom of its cell (the Anagen phase), the underlying structures will be heated and therefore destroyed: that particular hair will not grow again. If, on the other hand, the hair is in another phase (Catagen or Telogen), the heat will not be transmitted to the level of the underlying structures. Those structures will remain intact and will be able to generate a new hair. This is why several sessions are needed for treating each area.