Collagen Supplements is the most abundant protein in your body. It is the major component of connective tissues that make up several body parts, including tendons, ligaments, skin and muscles. Collagen has many important functions, including providing your skin with structure and strengthening your bones. In recent years, collagen supplements have become very popular. Most are hydrolyzed, which means the collagen has been broken down, making it easier for you to absorb.