FRONTLINE PLUS contains two active ingredients to break the flea life cycle at every stage. One ingredient, fipronil, kills the adult fleas on your pet while the other ingredient, (S)-methoprene, kills flea eggs and prevents larval and pupal development. (S)-methoprene prevents fertile flea eggs being laid throughout the month, preventing reinfestation of your pet and contamination of your home environment. 1,2,3,4,5,6. Fleas can breed all year round so ensure you continue to treat your pet in winter to achieve the best flea control. FRONTLINE Plus When applied correctly, FRONTLINE PLUS remains active on the skin of your pet for one month. Treat all of your dogs and cats every month with FRONTLINE PLUS. Use the stickers in the FRONTLINE PLUS pack to record the treatment dates on your calendar and sign up for the FRONTLINE PLUS reminder service to help you remember when your pet's FRONTLINE PLUS treatment is due. For paralysis tick control in dogs, use FRONTLINE PLUS every 2 weeks. (For paralysis tick control in cats, use FRONTLINE SPRAY every 3 weeks.)
