A nasal device for filtering air breathed into a user's nose is disclosed herein. In an embodiment, a nasal device includes a body sized and shaped to be secured to at least one of a user's nostrils, and a filter positioned on the body so as to be located over at least one of the user's nasal passages when the body is secured to the user's at least one nostril, wherein the filter filters air breathed into the user's at least one nasal passage when the body is secured to the user's at least one nostril.