Hyaluronic acid, a naturally-occurring component of viscous synovial fluid, may reduce joint pain associated with knee osteoarthritis. Because synovial fluid cushions joints, physicians sometimes inject hyaluronic acid into the knee to improve fluid effectiveness. In a meta-analysis of 22 clinical trails, researchers at Johns Hopkins Arthritis Center concluded patients treated with hyaluronic acid injections reported modest reductions in knee pain. They remarked, however, that most trials were poorly designed, and the placebo effect rather than the drug might be responsible for their reported pain relief.
When injected into the skin, hyaluronic acid-based fillers can reduce the appearance of wrinkles. They can also “plump” skin or lips and make them appear fuller. The Food and Drug Administration has approved multiple hyaluronic acid-based fillers, which it claims reduce fine lines and wrinkles. A 2010 French study found one hyaluronic acid-based preparation measurably reduced nasolabial folds, commonly known as “laugh lines.”
Your eyes and tears contain hyaluronic acid. A Japanese study published in the “British Journal of Ophthalmology” concluded a hyaluronic acid solution improved corneal epithelial disorders in dry eyes. The corneal epithelium is the outermost part of your eye. An Italian study published in the same journal in 2002 found that hyaluronic acid relieved dry eye in sufferers of Sjögren’s syndrome, an autoimmune disorder.