\n Hi, thank you for your question. This works great and is the same exact medication as frontline plus. How it works: Flea5X Plus contains fipronil, a slow-acting, broad-spectrum insecticide that disrupts the central nervous system of fleas and ticks. It also contains (S)-Methoprene, an insect growth regulator that helps to stop the flea life cycle by killing flea eggs and larvae. The waterproof formula means your pet will be protected even after swimming or bathing.\n