Yes. you should prepare your skin before your laser treatment. Shave the area you are going to treat and make sure that it is free of unwanted hair on the upper skin. Tria laser targets the melanin inside the hair follicle under the skin. If you don’t shave, the laser may not reach the hair follicle completely and will be wasted. Therefore, the treatment won’t be effective. You might feel skin burns if you don't shave properly.