Low-Level Light Therapy for Hair Growth and Alopecia Treatment

The talk reviews hair anatomy, the hair growth cycle, and common causes and types of alopecia, emphasizing that hair loss is both a cosmetic and functional problem with major genetic, hormonal, systemic, drug-related, and structural contributors. Current treatments include hair transplantation as the main gold standard for androgenic and other non-scarring alopecias, with minoxidil, finasteride, PRP, and excimer laser used as adjuncts. The main focus is low-level light therapy (LLLT), also called red light therapy, which was discovered serendipitously when irradiated mice grew hair. Although its exact mechanism is unknown, it is thought to influence hair cycling by promoting anagen reentry, prolonging anagen, increasing follicular proliferation, and preventing premature catagen. Clinical studies showed improved hair growth, density, thickness, and tensile strength in androgenic alopecia using 655 nm devices, laser combs, helmets, and other LED systems. The speaker also described animal studies where LLLT stimulated regrowth in heat-induced alopecia areata and sped recovery in chemotherapy-induced alopecia. Overall, LLLT appears safe and effective for stimulating hair growth, though optimal wavelengths and dosing parameters remain uncertain; reported side effects are usually mild, with transient telogen effluvium being the main concern.