Frontline Plus is a monthly topical flea and tick preventative for dogs and cats. Frontline Plus kills 100% of adult fleas on your pet within 18 hours and 100% of all ticks within 48 hours. Frontline Plus contains an insect growth regulator S-methoprene which kills flea eggs and larvae. Its effective against all stages of the brown dog tick the American dog tick the lone-star tick and the deer tick (the major carrier of Lyme disease). Frontline Plus remains waterproof for 30 days.