Laser hair removal, based on photothermal dynamics, involves the penetration of laser light into the skin's epidermal layer to reach the hair root. The pigmentation in the hair root absorbs this light energy and transforms it into heat energy, damaging the hair in the growth phase without harming the surrounding tissues.

Yes, gel is required. The gel serves a dual purpose by protecting the skin and enhancing the conduction of the laser to the hair root.