Hyaluronic Acid - Rooster Juice. Hyaluronic Acid is a natural substance found in all living organisms other than plants. Your own body makes it and it's found in your joints, eyeballs and skin. When isolated, it's a very thick, viscous liquid. It works as a lubricant and shock absorber in the knee, and more importantly, it's a natural pain inhibitor. Most Hyaluronic Acid for Joint Fluid Therapy is made from the combs of roosters. One of our patients referred to it as Rooster Juice, and that's been our nickname for it ever since. (So if you do an Internet search for more information, use the term Hyaluronic Acid, as the keyword Rooster Juice will get you nowhere!). There are several brands of Hyaluronic Acid.