FRONTLINE COMBO Spot-on Cats is an insecticidal and acaricide solution in spot-on form for cats. Thanks to the combination of its two active ingredients, Fipronil and (S)-methoprene, it is active on ticks, lice, adult fleas, flea eggs and larvae and preventing the appearance of new parasites. It combines the action of Fipronil, a fast-acting insecticidal substance and (S)-methoprene, an insect growth regulator (IGR), protecting the cat and the environment in which it lives from fleas.