Collagen is an essential, water-insoluble protein that constitutes a significant portion of our body. It is the fundamental building block of all connective tissues, including bones, joints, ligaments, tendons, and cartilage, making it a popular ingredient in joint health supplements. It is commonly used in the form of gelatin (denatured collagen) or collagen hydrolysate (denatured collagen broken down into smaller units called peptides). There are a total of 27 known types of collagen, but not all of them can be effectively absorbed when externally supplied. In addition to its role in joint health, collagen deficiency can also manifest as aging skin, poor hair quality, and weakened nails.