Angels' Eyes is the first product specifically developed to eliminate unsightly tear stains from the inside out! Angels' Eyes also helps to eliminate staining around the mouth and their coats due to licking. Other products are topical requiring high maintenance and yet will only remove the tear stains temporarily causing it to return worse than before. Angels' Eyes starts working before the tear stains begin and never adds food dyes or wheat which can have negative effects on your pet. All of Angel's Eyes ingredients are products of the USA