Collagen is the most abundant protein in your body, accounting for about one-third of its protein composition.

It’s one of the major building blocks of bones, skin, muscles, tendons, and ligaments. Collagen is also found in many other body parts, including blood vessels, corneas, and teeth.

You can think of it as the “glue” that holds all these things together. In fact, the word comes from the Greek word “kólla,” which means glue.