A laser hair comb works by emitting a low power laser beam onto the scalp. The scalp is exposed to the beams which helps promote hair growth. Studies have shown that increasing the action of a molecule called adenosine triphosphate may promote hair growth. Laser combs typically work by parting the hair (as you comb) to enable the laser light to pass through to the scalp and thus stimulating hair follicles.

Laser comb