Flea-free in a flash! ⚡ Administer daily if needed for ongoing protection. Perfect for cats and kittens 4 weeks and older. Experience flea-free bliss in just 30 minutes! Rest easy knowing it's safe for sensitive pets. Trust the experts with this proven solution. 30 min action 2-25 lbs safe 6 doses included Capstar (nitenpyram) is a fast-acting oral flea treatment for cats weighing 2-25 lbs. This vet-recommended medication starts killing adult fleas within 30 minutes and is safe for cats and kittens 4 weeks and older. Each package contains 6 doses, ensuring your furry friend stays flea-free with convenient, gluten-free tablets.