A swipe-and-smile secret weapon formulated for sensitive teeth. Gently brighten and deal with troublesome stains while lightening tooth enamel with science-backedingredients. How to use Twist the bottom of the pen until liquid rises to the tip. Using the brush, apply a small amount of liquid to your teeth, avoiding your tongue and gums. Leave for 10 minutes, then rinse with water. Use once a day, preferably at night, after brushing your teeth. Do not eat or drink for 30 minutes after use.