Some believe that they're allergic to the feathers inside the duvet. It is actually the dust mites that are attracted to the feathers that cause the allergic reactions. All our bedding is hypoallergenic. We use Nomite certified covers on all of our natural duvets and pillows. This means the fabric cover has been tested to the European Down and Feather Associations standards, and that the cover is so tightly woven, it won't allow any dust mites to get through into the filling.