The darker the hair (the richer in melanin) and the better the result. Light and fine hairs are more difficult to eliminate. White hairs or red hair cannot be removed using this method.
Since the skin also contains melanin, it is important that it is not too dark. Cutaneous melanin stops part of the light rays reaching the hair follicle and there is a large drop in efficiency as well as a high risk of pain or burns.
It is therefore necessary to completely avoid treating skin types 5 and 6, and to temporarily put off sessions with individuals who have too dark a tan.