Frontline® Plus (fipronil/methoprene) acts on the nervous system of fleas and ticks, causing paralysis and death of the parasite. Frontline Plus spreads over your pet's body via the natural oils in its skin, killing 98-100% of the fleas or ticks within 24-48 hours, and controls transmission of tick-borne disease. Frontline Plus combines fipronil and (S)-methoprene, an insect growth regulator (IGR), to provide the most effective spot-on flea and tick protection available for dogs and cats. Fipronil collects in the oils of the skin and hair follicles and then is released over time (up to 1 month) from the hair follicles onto the skin and hair. Methoprene stops flea larvae from developing into mature forms. Frontline Plus kills all stages of fleas on dogs for up to three months and for up to six weeks on cats, as well as the four major kinds of ticks that transmit serious diseases, including those that may carry Lyme disease. Frontline Plus stays on even with bathing, swimming, or exposure to sunlight. Approved for use on puppies 8 weeks of age and older. The convenient Remind Me system sends one dose of the medication out each month to keep your pet’s treatment on schedule.