LLLT works by slowing, and in some cases, reversing miniaturization. When the scalp is illuminated by red laser, light energy is absorbed by stem cells in the dermal papilla, a specialized region of the follicle near its base. These cells, which play a central role in controlling the hair cycle, and promoting hair growth, are energized when they absorb red laser light. Their ability to perform cellular respiration is enhanced, and their activity is increased.
As a result of this increased activity and a complex series of cellular and biochemical interactions, the hair follicle spends a greater amount of time in the growth phase of the hair cycle, thereby slowing or reversing miniaturization and the progression of thinning and balding. Blood flow is increased as well via these interactions, delivering much-needed nourishment to sustain the follicle.