Whitening your teeth and keeping your smile bright is a little like coloring your hair: maintaining your results requires maintenance. Your individual maintenance program depends on a number of factors, including lifestyle, age and original shade. We recommend first completing a full GLO whitening treatment (which is five to seven days) to achieve your desired shade. After that, maintain your teeth whitening results with one day of whitening each month (three back-to-back applications), followed by another five-to-seven-day full GLO whitening treatment after six months. That said, if you notice that your teeth are darkening sooner (or you feel like they could use some brightening), simply whiten with our GLO whitening gel, available in a pack of three convenient GLO Vials or more, as soon as you feel you need to - until you achieve your desired shade. Additional five- to seven-day treatments with your preferred GLO device can also be safely repeated until your desired result is achieved.