Capstar is a flea preventative that actively kills fleas and larvae are on your dog or cat. Within 30 minutes of application, Capstar gets to work by killing adult fleas on your dogs and cats. Does your cat have a bad flea problem? No Problem, Capstar is safe to use as much as once a day to kill off any bad flea infestations your pets may encounter. Is your puppy or kitten suffering from fleas? With it’s designed formula, Capstar is safe for kittens and puppies 4 weeks and older that weighs at least 2 pounds. It is even safe on nursing or pregnant dogs and cats! Capstar comes in tablets for both dogs and cats and are administered according to weight and pet type.