Hydroquinone, an over-the-counter drug that can bleach your skin, may fade dark spots. Retinoids may make your skin tone more even. One study says vitamin C helps fade age spots when you use it for 12 weeks. Kojic acid -- a chemical that's often used as an skin-whitening ingredient in products -- can do it, too.
When you use any of these, make sure to wear sunscreen. Your dark spots may come back if your skin gets too much sunlight.