The best way to lighten dark acne scars (or other dark marks on the skin) is a combination of topical medication, chemical peels and laser treatments. Your dermatologist can recommend the optimal combination for your skin type. These dark marks, called post-inflammatory hyperpigmentation, develop as a result of inflammation on the skin. There are prescription-strength medications (such as hydroquinone, azelaic acid, and tazorac) that can improve the appearance of dark spots on the skin. Chemical peels can also improve the dark spots, and can work more quickly than prescription medications alone. Laser treatments, such as the Fraxel laser, are the most effective option, though they sometimes take more than two weeks to deliver their optimal result.