Laser hair removal focuses on the endogenous chromophore melanin, which is mainly found in the hair shaft, with a small amount present in the upper third of the follicular epithelium (Figure 1). When an appropriate energy source (such as a laser) is directed at the skin, light is primarily absorbed in the hair shaft melanin. Heat is generated and diffuses to the surrounding follicular epithelium. A similar principle applies to laser treatment of vascular lesions, where the heat generated after absorption by hemoglobin is transferred from the blood to the vascular endothelial cells. .
