Whitening strips are thin, flexible plastic strips coated with a gel that contains a bleaching agent, usually hydrogen peroxide or carbamide peroxide. They are designed to be applied directly to the teeth for a specified period, typically ranging from 30 minutes to a few hours, depending on the product. These strips aim to remove stains and lighten the color of teeth, providing a brighter smile. Most whitening strips are available over-the-counter and come in various strengths and formulations. Users should follow the instructions carefully to achieve the best results while minimizing potential side effects, such as tooth sensitivity or gum irritation.