Capstar is an oral tablet that kills adult fleas on dogs and puppies four weeks of age and older. Capstar begins working within 30 minutes and achieved greater than 90% effectiveness against adult fleas on dogs within 4 hours and cats within 6 hours. Capstar can be used with lufenuron, i.e. Program® Flavor Tabs, to provide a flea management system. The two products when used together kill adult fleas and prevent flea eggs from hatching. A single dose of Capstar tablets should kill the adult fleas on your pet. If your pet gets re-infested with fleas, you can safely give another dose as often as once per day. Each tablet contains 57 mg of Nitenpyram. Shipping weight: 1/6 lb.