So, to answer your questions: The phlegm itself isn't toxic or harmful to swallow. Once swallowed, it's digested and absorbed. It isn't recycled intact; your body makes more in the lungs, nose and sinuses. It doesn't prolong your illness or lead to infection or complications in other parts of your body.

Where does mucus go when you swallow it?

Wherever it's produced, mucus is a mix of water and proteins, and most of it gets pushed to the back of your throat by microscopic hairs called cilia. Whether you're aware of it or not, you're constantly swallowing all this mucus, and it harmlessly ends up in your stomach.

Can you swallow mucus to get rid of it?

So here's the big question: Do you spit or swallow your phlegm? Even though it might taste nasty, “there's nothing wrong with swallowing it,” Dr. Comer says. In fact, that's probably what your body expects you to do, which is why phlegm naturally drains down into the back of your throat.