GLO teeth whitening gel is specially formulated to stick to your teeth. There, the thick whitening gel penetrates, whitens and then evaporates as it breaks down safely into oxygen and water - without harmful byproducts. Inconvenient and conspicuous strips are only needed to keep drippy or runny gel in place. It is so much easier to simply brush on GLO whitening gel and go on about your day. No one will even know you are whitening your teeth.