Frontline Plus is a topical flea and tick treatment for cats that kills fleas and ticks within 12 hours. It contains two active ingredients, fipronil and (S)-methoprene, which work together to kill all life stages of fleas and ticks for up to 4 weeks. Frontline Plus is applied directly to the skin between the shoulder blades and spreads over the whole body within a day. It is suitable for use on cats and kittens over 8 weeks old, including breeding and nursing queens.