These all-beef collagen springs are 100% natural and are free from grain, gluten, wheat, corn, and soy. They are naturally rich in chondroitin and glucosamine, which support healthy joints, healthy skin, and a beautiful, shiny coat. Redbarn's Collagen Chews are packed with protein! Collagen is a protein found below the top layer of skin in both animals and humans. It is one of the key components of connective tissues. Think of it as the glue' that helps hold the body together. Collagen has higher protein and less fat than traditional rawhide treats and digests much easier.