Capstar is an effective and fast-acting treatment that kills adult fleas and is indicated for treating flea infestation in dogs and puppies. It comes in a tablet form that contains a fast-acting adulticide which provides quick relief from fleas. Capstar is a flavorless tablet which can be administered at any time when you see fleas on your pet. This tablet contains Nitenpyram as an active ingredient which is a neurotoxin that interferes with normal nerve transmission and destroys fleas. Capstar starts showing results within an hour of administration and kills 100% fleas within 7 hours. The tablet is recommended for puppies and dogs at least 4 weeks of age.