How to Whiten Teeth with Banana Peel whiten teeth with banana peel To whiten teeth with banana peel is very safe and healthy for teeth as banana peels are a wonderful source of minerals and vitamins. They do not have the abrasiveness that other natural whiteners have and best of all they are inexpensive. Risk of Side Effects Gum irritation and tooth sensitivity remain the two biggest complaints of in-home teeth whitening systems. The more exposure the teeth have to the whitening substance, the more likely it is that such side effects will develop, according to Harvard Medical School. Bottom Line Wear trays for two to four hours a day at a minimum and no longer than overnight depending on the strength of the bleaching agent, as recommended by the University of Maryland Medical Center.