Low-level laser therapy is a safe form of light/heat treatment under investigation for a variety of health indications. It is being used to treat the genetic forms of hair loss common in men and women, androgenetic alopecia or pattern balding. Low-level laser therapy is also called red light therapy, cold laser, soft laser, bio-stimulation and photobiomodulation.

Laser therapy used for hair loss treatment depends on devices that emit a light that can penetrate the scalp. Excimer (308 nm), helium-neon (632.8 nm), and fractional erbium-glass (1550 nm) lasers have been used. Low-level laser therapy (LLLT) uses devices with diodes that emit red light (wavelength 630-670 nanometers) Low-level laser therapy is intended for men and women with thinning hair or pattern baldness caused by a hereditary condition.

Physicians use a system known as the Norwood-Hamilton Classification (men) and the Ludwig-Savin Scale(women) to describe the degree of hair loss. Low-level laser therapy is intended for the promotion of hair growth in males who have Norwood Hamilton Classifications of IIa to V and in females who have Ludwig (Savin) I-4, II-1, II-2, or frontal patterns of hair loss and have Fitzpatrick skin phototypes I to IV.