Joints are like gears – they work best if they’re well lubricated. In a healthy joint, a thick substance called synovial fluid provides lubrication, allowing bones to glide against one another. Synovial fluid acts as a shock absorber, too. In people with osteoarthritis, a critical substance in synovial fluid known as hyaluronic acid breaks down. Loss of hyaluronic acid appears to contribute to joint pain and stiffness.

That begs the question: Will replacing hyaluronic acid relieve osteoarthritis symptoms? Hyaluronic acid injections (also known as viscosupplements) are approved by the U.S. Food and Drug Administration (FDA) for treating osteoarthritis of the knee, though some doctors have used the therapy on other joints, such as the hip and ankle. While studies of hyaluronic acid injections have occasionally yielded disappointing results, many doctors who treat osteoarthritis say that the weight of scientific evidence – and their own clinical experience – suggests that a shot in the knee can produce significant relief for some patients. Furthermore, lab and clinical research hints that hyaluronic acid may do much more than simply re-grease a creaky joint.

An Alternative to NSAIDs

The idea of using hyaluronic acid to treat osteoarthritis was originally proposed 70 years ago by Hungarian scientist Endre A. Balasz. By 1987, hyaluronic acid treatments were being used overseas, though the first viscosupplement available in the United States, Hyalgan, wasn’t approved by the FDA until 10 years later. There are now five hyaluronic acid treatments for knee osteoarthritis in use in this country. Hyalgan, along with Orthovisc, Supartz and Synvisc are made from a surprising raw material: rooster or chicken combs. Euflexxa is derived from bacteria.

Hyaluronic acid injections are one treatment option doctors may offer when a patient is no longer able to control osteoarthritis pain with ibuprofen or other nonsteroidal anti-inflammatory drugs (NSAIDs), or the patient can’t tolerate these drugs (which can cause side effects such as stomach bleeding and kidney problems). The treatment regimen for hyaluronic acid usually involves receiving one injection in the affected joint per week for three to five weeks. Many patients appear to get at least some relief – eventually.