Below is a pictorial representation of these cycles.
After the catagen phase, the hair enters the Telogen Phase, which is when the hair follicle rests and the hair falls out. This fall out of each individual hair is controlled by the genes and since hairs enter the Telogen Phase at different times, hair loss is usually not noticable. This phase usually lasts about 3 months and the whole cycle repeats itself when androgenetic alopecia is not present. If you have androgenetic alopecia, then hairs tend to stay in the telogen phase and hair takes on a wispy unpigmented appearance refered to as vellus hairs. Hair at this stage in androgenetic alopecia does not regenerate and can lead to follicle death which is irreversible.
The key to treatment of genetic diseases of the hair is to restore the normal cycle of growth in the hair follicle. Some drugs proven effective for hair loss act on signally pathways to stimulate the hairs to enter the Anagen phase. On the other hand, it is hypothesized that the HairMax LaserComb acts as an Anagen inductor through the process of photo-biostimulation. This means that the laser energy of the HairMax causes cell proliferation in the epithelia of the hair follicle marked by thicker hair growth and an increase in shedding of Catagen hairs at the onset of treatment and stimulation of entry into the Anagen or growth phase of the cycle. Since the dermal papilla consists of certain fibroblasts and specialized matrix cells at the base of the hair follicle, the laser light of the HairMax apparently interacts with these cells causing cell proliferation.
In conclusion, the cycles of hair growth are a complex mechanism that is not completely understood as to how they are controlled. However, research continues in an attempt to understand why the signaling system of the normal hair follicle is interrupted. Other research is focused on the role that photo-biostimulation plays in devices such as the HairMax LaserComb in the stimulation of hair regrowth. In the years to come, there will be a greater understanding of the reasons for hair loss and this will lead to the introduction of many other efficacious treatments including more widespread use of laser energy to treat diseases of the hair.