After just seven days of brushing, each of us saw definitively brighter smiles. One tester, who had whitened his teeth before, experienced the most dramatic lightening. But a whitening virgin also happily reported a noticeable boost in brightness and reduction in dark staining. All without any teeth or gum sensitivity—a big plus for anyone who's suffered through post-whitening pain in the past. Another plus? This stuff really polishes your teeth too. They look and feel extra clean and the shine makes them look even whiter.