Take the Purina One 21 day program and you could see a visible difference in your cat's health. Join today, and receive a FREE 150G SAMPLE to kick-start the journey with your cat! The 21 Day Program is on a mission to help more cats lead happier, healthier lives. You'll receive a free 150g sample pack to aid the transition from your cat’s current food to Purina One. This offer has expired, check out some of our great other offers still available here.