Collagen is an essential protein in the body, making up 70% of the protein within our skin and providing structure to our hair, nails, bones, ligaments and tendons. By the age of 25, natural collagen levels in the body start to decrease by 1-2% a year, reducing by almost a third by the time we reach 40 (sob).Because collagen is a protein found mostly in hair, skin, nails, bones and ligaments, this comes from animal sources, such as cows or fish. There will be products that claim to be vegan collagen, however they will likely only include ingredients that boost your natural production of collagen rather than supplementing with actual collagen.