Laser hair removal must be done on shaved skin (contrary to popular belief, studies have shown that shaving does not produce thicker and darker hair) so that the hair is not more than a mm. or few above the epidermis, otherwise the longer hairs would rest against the skin as the laser handpiece is applied to the skin surface, and the hair shaft would abosrb the energy transmitting heat to the surface of the skin. This would increase the risk of skin color changes and even a blister or burn. Waxing or plucking should not be done shortly before the treatment as this would remove the hair bulb, or target of laser energy absorption. As the hairs regrow and reach the surface, you can retreat.