We recommend 10-30 minutes of treatment each day and 7-14 days of consecutive use until desired whitening results are achieved. If you have sensitivity, then take a break for 1-2 days, and continue the treatment. After completing your full 12+ treatments, results can last up to 4-5 weeks. Depending on your lifestyle, for longer-lasting results, try to limit your intake of any teeth-staining foods or drinks such as coffee and tea, wine, soda, and even some fruits when possible. Smoking cigarettes can also cause your teeth to stain more quickly. By using your Teeth Whitening System regularly, you can maintain your brilliant smile while preventing future stains from occurring. Our Teeth Whitening Pens are also ideal for maintaining your smile between treatments. By keeping your Whitening Kit stocked with Gel/Pen refills, you’ll ensure that your teeth stay whiter and brighter.﻿﻿Results may vary from person to person depending on personal factors such as genetic makeup, how stained your teeth are and what is causing your stain.