Sun damage, hormonal changes, or any other skin condition may be the main causes of pigmentation and dark spots. For successful treatment, there are a number of options including topical creams, chemical peels, and laser therapy. These processes can be of great value to the skin lightening and pigmentation decreasing purposes. Usually, visible changes might appear in only a few weeks to months, depending on the operational technique. Results along with the cost should be expected for about $150-$400 per session. For achieving the most effective results in your case and to make the treatment a more individual-based one, I am advising visiting a dermatologist. They can give you a diagnosis and advice, so you can select the most suitable and the safest solution for your skin.