Skin lightening is defined as "the practice of using chemicals or any other product with depigmenting potential in an attempt to lighten skin tone or improve the complexion; these goals are achieved by decreasing the concentration of melanin to achieve a reduction in the physiological pigmentation of the skin". Products used to achieve this purpose are known as depigmenting, skin-lightening, skin-bleaching, skin-brightening or skin-evening agents. Skin-whitening products containing highly toxic active ingredients (in particular mercury derivatives, hydroquinone and corticosteroids) are easily found on the market; the use of these depigmenting agents can be followed by a variety of adverse effects, with very serious and sometimes fatal complications, and is currently an emerging health concern in many countries.