The short answer to this question is YES.
Laser hair removal machines work by destroying hair follicles at their roots. The pigment of our hair follicles is what absorbs the light delivered by the laser causing the damage. When there is visible hair above the level of the follicle root, then the pigment in this hair will absorb the energy delivered by the laser. This not only increases the chances of burning and pain, but it also prevents the hair follicle from being destroyed at its root. In order to get the best results of laser hair removal treatment, it is recommended to shave the area being treated the night before or the morning of your laser hair removal appointment.