Hair Growth Stimulation reported in Laser Hair Removal Patients

Physicians who routinely perform hair removal using lasers (IPL, Nd:YAG, 755nm Alexandrite and others) have reported that they have often noticed hair stimulation within the treated area and nearby surrounding areas.     It is believed that when 'sub-therapeutic' thermal energy is delivered to the follicles that are the target of 'hair reduction,' that this may induce an unwanted increase in hair growth.    While this has been reported consistently in the medical literature, the mechanism is still unknown.    The physicians who published this report, http://www.typepad.com/t/app/control/files?__mode=show_link&file=photostimhair.pdf, believe that the laser induced terminal differentiation, instead of miniaturization, more often in those patients who had thinner, finer (vellous) hair on the areas being treated.    On the heels of the recent fda-clearance of the first laser therapy device for the promotion of hair growth, these reports may help give us a clue as to why low level laser hair therapy seems to help improve the quantity and quality of scalp hair growth in patients with hereditary hair loss.   It may also help us determine which hair loss patients can be expected to have better results with laser therapy.