With 3 active ingredients, you can give your dog protection against a variety of irritating pests. The K9 Advantix® topical formula kills and repels all stages of fleas within 12 hours, with an IGR (Insect Growth Regulator) to provide additional protection against the development of flea eggs and larvae. It also kills ticks, mosquitoes and lice and repels biting flies. After eliminating fleas on your dog, it also prevents the fleas on treated dogs from reinfesting your home. Active ingredients: Imidacloprid, Permethrin and Pyriproxyfen.