Used as a nasal decongestant in over-the-counter and prescription medications to relieve nasal congestion caused by colds, allergies, or sinusitis. It works by constricting blood vessels in the nasal passages, reducing swelling and improving airflow. Commonly found in nasal sprays and drops, it provides rapid relief, typically within minutes, lasting up to 10 hours. Also used to prepare nasal passages before certain medical procedures or examinations. Not recommended for prolonged use due to risk of rebound congestion.