Types of Collagen and Their Sources Understanding the different types of collagen is essential for consumers looking to choose the right product for their needs. There are at least 16 types of collagen, but the most prevalent in supplements are Types I, II, and III. Type I collagen, primarily found in skin, tendons, and bones, is often the focus of beauty products. Type II collagen, on the other hand, is primarily found in cartilage and is particularly beneficial for joint health. Type III col...