Allegra® contains fexofenadine hydrochloride, a selective H1-receptor antagonist that helps block the effects of histamine, one of the primary mediators responsible for allergic reactions. By preventing histamine from binding to its receptors, fexofenadine helps relieve common allergy symptoms without causing significant drowsiness in most individuals.

The medication is widely used for the treatment of seasonal allergic rhinitis (hay fever) and chronic idiopathic urticaria (chronic hives). It effectively reduces sneezing, itchy or watery eyes, nasal congestion, itching of the nose or throat, and allergy-related skin symptoms.

As a second-generation antihistamine, fexofenadine offers long-lasting symptom control with once-daily dosing and minimal penetration into the central nervous system, making it a preferred option for patients seeking non-sedating allergy relief.

Treatment decisions, dosing schedules, and duration of therapy should always be determined by a qualified healthcare professional.