What is hyaluronic acid?
Hyaluronic acid is a polysaccharide (a complex sugar) and it is one of the major components of the scaffolding known as the extracellular matrix of the skin. It’s not just found in skin. It is also found in the synovial fluid that surrounds joints, as well as cartilage and in the tissues of the eye.
What does it do?
Apart from being a physical part of that extracellular matrix, hyaluronic acid also plays an important role function of the skin itself. (1) It seems to play a critical role in repair of damaged cells, helping fibroblasts make more connective tissues. Research tells us that when it gets into the skin itself, it helps regain elasticity and moisture. (2)
Sounds awesome? It is!
It does have a downside though. It has a very high molecular weight. What that means practically is it is hard to get it into the skin.
It can be injected into the skin. In fact hyaluronic acid is the major ingredient of “fillers” that are injected to plump the lips and cheeks. Getting it into the skin by simply adding it to a cream or ointment has been more fraught. (3) After all, if it can’t penetrate the skin barrier, and actually get into the skin, it can’t do much beside moisturise.
Researchers are busily studying low molecular weight hyaluronic acid which might be able to get through the skin barrier. Whether it has the same wonderful results remains to be seen! But as things stand, there is no evidence for topical application of Hyaluronic acid.