Allegra (Fexofenadine) is an antihistamine used to treat seasonal allergies and hives. It works by blocking the effects of natural substances that cause allergy symptoms. It is available in tablet and liquid form and is taken orally. Allegra is a fast-acting medication that provides relief from allergy symptoms within 1 to 3 hours. It can be purchased online from our website and is delivered to your door in the US.