Philips Zoom NiteWhite is applied to a mouth guard or retainer before being worn over teeth:
• Brush and floss your teeth
• In a counterclockwise motion, twist off the clear plastic cap from syringe
• Place a small amount of gel in each tooth compartment of the tray before applying the retainer to your teeth. Remove any excess gel on gums with your finger or a dry toothbrush.
• Wear 2-4 hours once daily or overnight.
Once the desired shade has been reached, continue to apply Philips Zoom NiteWhite once every two weeks to maintain your white teeth.
Please find full instructions here.