Nasonex (generic: mometasone) is a prescription medication used to treat nasal allergy symptoms including runny, stuffy, itchy nose and sneezing related to allergies, and nasal polyps. Nasonex belongs to a group of drugs called topical steroids. It works by affecting the immune system which decreases swelling of the nasal passages.

This medication comes in the form of a nasal spray which is inhaled through the nose, once or twice a day, in each nostril.

Common side effects of Nasonex include headaches, viral infections, sore throat, and nosebleeds.