Question: what is the difference between frontline and hartz ultraguard?
Answer: In addition, Frontline Plus® for cats contains two ingredients, Fipronil and Methoprene. Methoprene is the same ingredient used in Hartz UltraGuard® Flea Egg & Flea Larvae treatment for Cats and Kittens. However, our UltraGuard product contains just 2.9% Methoprene, where Frontline Plus® contains 11.8%.