What is Collagen Protein? Collagen is the main structural protein in the body and a vital building block for nutrition. With a strong presence in hair, skin, nails and joints of both men and women, Collagen has become the most popular ingredient in Beauty Products today.* There are at least 16 types of collagen but roughly 80-90% of the Collagen in the body consists of type 1, 2 and 3. These Collagen types are found naturally in many food sources and added to nutritional supplements & vitamins.