Listerine whitening strips are water-soluble strips that whiten the teeth. They fully dissolve in the mouth five to 10 minutes after application. The main active ingredient is hydrogen peroxide, a highly common whitening agent.
Listerine states that the product will create noticeably whiter teeth after two weeks of continued use. The company also claims the product will reduce bacteria associated with bad breath by 99 percent.
Brushing before applying the strips is a vital step in increasing their effectiveness. However, no brushing or rinsing is necessary after application. The strips will simply dissolve in the saliva and are not hazardous to the digestive track.