The vast majority of animal rights advocates adopt vegetarian or vegan diets. They may also avoid clothes made of animal skins, such as leather shoes, and will not use products known to contain animal byproducts. Goods containing ingredients that have been tested on animals are also avoided where possible. Company-wide boycotts are common. The Procter & Gamble corporation, for example, tests many of its products on animals, leading many animal rights advocates to boycott the company's products entirely, whether tested on animals or not.