Eldoquin (for the skin) is used to lighten areas of darkened skin such as freckles, age spots, melasma (sun damage), or chloasma (darkened skin caused by hormonal changes). Hydroquinone is used to lighten the dark patches of skin (also called hyperpigmentation, melasma, "liver spots," "age spots," freckles) caused by pregnancy, birth control pills, hormone medicine, or injury to the skin. This medicine works by blocking the process in the skin that leads to discoloration. A valid prescription should be available upon delivery