The toothpaste works by using a mineral derivative that lifts surface stains without bleach or peroxide that cause the pain & sensitivity. It’s a patented formula called AP-24 which also coats the enamel to help prevent plaque and future stains throughout the day. Each tube lasts for about 2.5 months when used twice a day. This replaces bleaching trays, strips as well as just normal toothpaste. For best results, dry brush.