Laser hair reduction is a medical procedure that uses an intense pusating beam of light to remove unwanted body hair. Laser hair removal works by passing a light beam through the skin. The laser targets dark pigment, called melanin, in hair. When the light beam hits the hair follicle (where hair growth originates), the intense heat destroys the hair follicle.
Laser hair reduction requires multiple treatmetns, because hair can only be effectively treated when it is in a stage of growth termed the anagen phase. Since hair grows in cycles and does not enter the anagen phase at once, sessions for laser hair removal are spread out to treat new hair growth that was 'dormant' in previous sessions. The number of sessions required varies between people.
Laser hair reduction is not recommended for everyone, the darker the hair, the more melanin it contains. If hair is lighter than the surrounding skin, the skin will absorb more heat than the hair. Therefore a person with blonde hair is the wrong candidate for laser hair removal while a fair person with dark hair is the ideal patient.