Frontline Plus contains two active ingredients: fipronil, which kills both ticks and adult fleas, and S-methoprene, which keeps flea eggs from hatching and stops the growth of flea larvae.

Popular flea and tick products were sent to a certified lab, which found that: Frontline Plus for Dogs, a popular topical flea and tick product, contains 2,390 parts per trillion (ppt) of four ...

If you're looking for an over-the-counter (OTC) medicine available without a prescription, Frontline Plus for Cats is your best bet. Before buying any flea treatment, ask your veterinarian which ...