Low-Level Light Therapy and Hair Loss

In 2011, low-level light therapy was a relatively new treatment for hair loss, using low power, red to near-infrared light produced by a laser or a light emitting diode. The FDA approved it in 2007 for treating mild to moderate male pattern hair loss, the most common type of hair loss in men. It was also used for female pattern hair loss and other conditions like alopecia areata, telogen effluvium, and post-transplantation surgery. The therapy was associated with decreased hair loss rate, increased non-vellous or terminal hair, and improved hair texture. Side effects included initial increase in hair loss, pruritis, and increased blood flow. The therapy worked by increasing the hair follicle's metabolism using the light's energy, theoretically leading to hair growth. However, there were limited studies supporting its use and it was unclear which individuals responded best to this treatment.