Experience visibly whiter teeth in just 1 week* with the Colgate Optic White Overnight Teeth Whitening Pen. This Colgate whitening pen contains 21 nightly treatments and has a hydrogen peroxide-based formula that is enamel-safe and designed for no tooth sensitivity**. To use the teeth gel whitening pen, follow your regular brushing routine. Next, dry your teeth, then paint the whitening gel onto clean, dry teeth. The serum dries within seconds and will stay on your teeth overnight while you sleep. To remove the dried whitening gel serum, simply brush your teeth like normal when you wake up the next morning and enjoy a whiter smile. Repeat treatment nightly for 1-3 weeks in a row for best whitening results. Get glowing and start living your life to the brightest with the Colgate Optic White Overnight Teeth Whitening Pen. *when used as directed **during and after the whitening process.