100 % NATURAL! containing POTENT ingredients researched to help CALM the histamine response. HISTAMINE is produced by the body in response to an allergen; whether DUST, MOLDS, POLLEN or other PARTICULATES. The reaction produced by the body (histamine response) causes runny noses/eyes, head tossing, itch, head shaking, cough, snorting and sneezing in the horse. By CALMING the histamine response the horse is also much calmer as a result with fewer symptoms.