Hyaluronic acid, sometimes referred to as ‘the fountain of youth’, is known to many of us as a ‘hot’ new ingredient in skin creams. HA is a polysaccharide (a type of carbohydrate molecule) naturally present in the human body. Levels decline with age, and supplements are often recommended to treat or prevent ageing-related health problems. It is found in the highest concentrations in fluids in the eyes and joints, and in connective tissue, and it helps the body resist wear and tear. What exactly is it, and does it have other benefits?