What is the active ingredient in phenylephrine?

The active ingredient in phenylephrine is phenylephrine hydrochloride. It is a sympathomimetic amine that primarily acts as a decongestant by constricting blood vessels in the nasal passages, reducing swelling and congestion. Phenylephrine is commonly used in over-the-counter medications to relieve nasal congestion due to colds, Allergies, or sinus infections.