NOW&ampreg; Double Strength Hyaluronic Acid has twice the Hyaluronic Acid (100 mg per capsule) as in our regular strength product (50 mg per capsule). Hyaluronic Acid is a compound present in every tissue of the body, with the highest concentrations occurring in connective tissues such as skin and cartilage. Hyaluronic Acid is an important constituent of joint fluid, where it serves as a lubricant and plays a role in resisting compressive forces.*