Frontline Gold for Cats doesn’t just kill adult fleas and ticks, but also slays the next generation of flea eggs and larvae. Even faster than Frontline Plus, Frontline Gold starts working within 30 minutes and lasts for 30 days! It works because of two, tough killing ingredients. The first, fipronil, kills adult fleas and ticks. The second, (S)-methoprene, attacks flea eggs and larvae. They work together to kill all month long. Plus, it breaks the flea life cycle. By also destroying the next generation of flea eggs and larvae, Frontline Gold gives you the power to help prevent a flea infestation on your pet. Frontline products are highly recommended by veterinarians for flea and tick control for cats.