This hair reduction therapy targets melanin which occurs naturally in the skin and gives skin and hair its color. Know more about laser hair reduction
The idea behind laser hair reduction is something called selective photothermolysis (SPTL) which basically means targeting a structure or tissue using a specific wavelength of light with the intention of absorbing light into that target area alone. In the case of laser hair reduction, lasers cause localised damage by selectively heating dark target matter (melanin) in the area that causes hair growth (the follicle) while not heating the rest of the skin.
Hair reduction lasers selectively target melanin which occurs naturally in the skin and gives skin and hair its colour. There are two types of melanin in the hair: eumelanin (which gives hair brown or black colour) and pheomelanin (which gives hair a blonde or red colour). Because of the selective absorption of photons of laser light, black or brown hair is usually more easily removed while blonde or red hair does not respond well to laser hair reduction.