Used as a nasal decongestant to relieve stuffy nose caused by colds, allergies, or sinus inflammation. It works by narrowing blood vessels in the nasal passages, reducing swelling and congestion. Found in over-the-counter nasal sprays and drops for short-term relief. Also used in some eye drops to reduce redness by constricting blood vessels. Not recommended for prolonged use due to risk of rebound congestion.