Collagen is the most abundant protein in the human body, and it accounts for over 30% of the bodys protein. Collagen is present in all connective tissues such as skin, bones, cartilage, tendons, ligaments and blood vessels. As the structural framework of the body, collagen plays a crucial role in supporting and connecting everything together. Collagen can also be found in the eyes, ears, nose cartilage, teeth, lungs, blood vessels and muscles.