Used as a nasal decongestant in over-the-counter and prescription sprays and drops 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. Often found in products for short-term relief of blocked nose. Also used in some ear drops to reduce swelling in the Eustachian tube. Not recommended for prolonged use due to risk of rebound congestion.