Euflexxa (3x2ml)How does Euflexxa work? The main active ingredient, hyaluronic acid (HA) is a natural substance found inside the human body. It's key properties are to keep the knee lubricated. HA naturally breaks down in the body during metabolism and is then replaced. However as we get older and our metabolism slows down, replacement of HA is less often which results in less lubrication around the joints that we use most frequently. Euflexxa imitates the natural HA