FRONTLINE® Gold for Cats' triple action formula kills adult fleas, flea eggs and larvae, and ticks for a full month. Regular use of FRONTLINE® Gold for Cats controls and prevents flea infestations and works to break the flea life cycle with its three active ingredients – fipronil, (S)-methoprene and pyriproxyfen. (Reference: *Data on file at Boehringer Ingelheim.)