¿Qué es la depilación láser y cómo funciona?

Laser hair removal is based on the principle of selective photothermolysis.

The target tissue (ie the hair) absorbs light-energy of a very specific wavelength resulting in a sharp rise in temperature with the ultimate goal of destroying it and all regenerative structures of the hair follicle (stem cells, bulb melanocytes, nipple and bulge point) The temperature at which the hair follicle develops is 70 degrees Celsius.

But what is the correct radiation wavelength? Below 600nm the penetration depth of the radiation is always less than 1mm but as the wavelength increases so does the penetrating capacity of the laser beam. So the longer the wavelength, the more effective it is in destroying the deeper hairs (eg back). deep skin structures. Melanin is effectively absorbed in the range of the electromagnetic spectrum between 600nm-1100nm. Above 600nm they strongly absorb blood vessels and those above 1100nm are strongly absorbed by water. Therefore these wavelengths are prohibitive and can not be used to remove hair.

The wavelengths available for laser hair removal in the range between 600nm-1100nm are:

• 694nm (Ruby laser)

• 755 (Alexandrite laser)

• 800-810nm (Diode laser)

• 1064nm (Nd: YAGlaser)

• 600-1100nm (IPLs-wide spectrum pulsed light source)

In order for laser hair removal to be effective, the following conditions must be met and taken into account:

The three key points in the hair follicle that need to be destroyed (all three) and contain melanin are: the bulb, the nipple and the bulge point.

Laser hair removal should be done in the regenerative growth stage of the hair because then the melanin is in a greater concentration, the hair is smaller, has a more superficial position and is more vulnerable to laser radiation at this stage. That is why the sessions are set every 6 weeks to achieve them at this stage. So when the hair is destroyed in the regenerative stage we need fewer laser sessions and the total duration of hair destruction takes less time.

The type of hair that the laser is applied must be the final hair, that is, the darker, harder and blacker the hairs are, the more intensely they absorb the laser radiation and the faster they are destroyed.

The density and depth of the hair depend on the area of the body that is located. That is why it is important that the wavelength of the laser is ideal to reach the right depth. Also depending on the area of the body depends on the duration of its developmental stage. hair. The shorter the growth stage of a hair, the sooner the session should take place. This also explains why not all the hairs in different areas of the body are destroyed at the same time.