LO was really stuffy and sick last week, so I tried it ....and it worked awesome! But now I am sicker than I have been in years. This is probably a common sense thing, but even with the filter you are breathing germs directly into your throat and chest. Thus, making mommy and daddy so sick and idiots. Read online that people suggest only using to clear mucus not related to a cold but there is no warning on the box. Thought I would pass this along to anyone else who may think about using it. Viva la blue sucker.