Sodium hyaluronate is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. The average 70 kg (154 lbs) person has roughly 15 g of sodium hyaluronate in the body, one-third of which is turned over (degraded and synthesized) every day. Sodium hyaluronate is also a component of the group A streptococcal extracellular capsule.

Sodium hyaluronate is used in eye surgery i.e., corneal transplantation, cataract surgery, glaucoma surgery, surgery to repair retinal detachment and.

Sodium hyaluronate is used as a viscosupplement, eye lubricant as an solution administered through a series of injections into the knee, increasing the viscosity of the synovial fluid, which helps lubricate, cushion and reduce pain in the joint. It is generally used as a last resort before surgery and provides symptomatic relief, by recovering the viscoelasticity of the articular fluid, and by stimulating new production from synovial fluid. Use of sodium hyaluronate may reduce the need for joint replacement

(C₁₄H₂₀NNaO₁₁)_n