For years, the go-to choice for allergy relief was an antihistamine, usually in the form of a pill. But antihistamines only block histamine, just one of the many allergic substances your immune system releases when you’re exposed to an allergen.*ii An OTC allergy spray that’s formulated with corticosteroids—a type of medicine approved by the FDA to treat nasal allergy symptoms—provides more complete relief† of total nasal symptoms than an antihistamine.iii Nasal sprays with corticosteroids block a variety of allergic substances. For example, FLONASE helps block six key allergic substances, including histamine, to treat your symptoms.*