TRI-ACTA H.A. adds Hyaluronic Acid to our popular TRI-ACTA formula to give even greater results. Combined with Glucosamine, MSM and Chondroitin Sulphate, TRI-ACTA H.A. is a comprehensive joint supplement helping to ensure sound joint function. Hyaluronic Acid is a substance found in all vertebrates, mainly in connective tissue such as cartilage, bone, skin, and body fluids.