Photobiomodulation for the Management of Alopecia: Mechanisms of Action, Patient Selection, and Perspectives

The 2019 document discussed the use of Photobiomodulation (PBM), a light therapy, for treating various types of alopecia. PBM was found to stimulate hair growth by increasing cellular metabolism, reducing inflammation, and prolonging the anagen phase in hair follicles. The effectiveness of PBM was dependent on the patient's characteristics and the parameters of the PBM device used. PBM devices, which include handheld combs, headbands, caps, and stationary hoods, were typically used for 10-20 minutes per day, delivering an energy density of 4 J/cm2. Clinical trials showed significant improvements in hair regrowth in both men and women using PBM devices. However, the benefits were gradual, and treatment should ideally commence at the earliest stage of self-perceived thinning hair. The document concluded that more research was needed to determine the optimal parameters for treatment and to understand the long-term effects.