Hyaluronic acid is present in every tissue of the body, and it performs many important functions. It helps deliver nutrients to and carry toxins from cells that do not have a blood supply, such as those found in cartilage; without adequate amounts of HA, the joints will become brittle and deteriorate. Not only does it keep joints lubricated, but hyaluronic acid also encourages water retention in other bodily tissues. It is found in large concentrations in the extracellular matrix (ECM), which is the fluid-filled space between cells. HA locks moisture into the ECM, keeping collagen and elastin moist and promoting a youthful appearance.