Conditions Back ConditionsDrugs & Supplements Back Drugs & SupplementsWell-Being Back Well-BeingMore Back More Privacy & More Subscribe Log In Search Subscribe GuideOverview Symptoms & Types Tests & DiagnosisTreatmentLiving With View Full Guide What Are Hyaluronic Acid Joint Injections?Written by Medically Reviewed by David Zelman, MD on September 13, 20232 min readIf you have that affects your knees, an injection of could help ease your pain and stiffness.People with get these shots to help lubricate their joints so that they work more smoothly.Your doctor can let you know if it would help you based on your symptoms and other treatments you’ve tried. Though the shots have been available for more than a decade, studies on how effective they are have shown mixed results.How They Work  Normal synovial fluid contains a substance present throughout the body's soft tissues. It helps lubricate your joints. If you have osteoarthritis, your supply of synovial fluid has thinned.The procedure is simple. Your doctor injects hyaluronic acid directly into your knee joint. Most people get a shot a week for 3 to 5 weeks. The FDA has only approved this treatment for people with osteoarthritis of the knee, but some people get it in other joints as well.There are different brands of hyaluronic acid that haven't been shown to differ in their effectiveness. Will This Treatment Help You?Hyaluronic acid joint injections don’t work for everyone. The research is mixed on how well they work. They seem to work better for some people than for others. If you are older or have advanced osteoarthritis, you may be less likely to find relief from this treatment.What to ConsiderUsually, people only try hyaluronan when treatments like physical therapy, exercise, and injections with painkillers and steroids don’t provide enough help.One advantage is that the side effects, such as swelling and discomfort on the area of your skin where you get the shot, are mild. Since the risks are small, your doctor may think that hyaluronan is worth a try, especially if your only other option is surgery.Hyaluronan may also be a good choice if you have trouble with side effects of other treatments. For instance, some people can’t take common painkillers such as aspirin, , or naproxen because of the risk of . And steroid injections, another common treatment for osteoarthritis, can harm your joints if overused.Check with your insurance company before you start this treatment. Some cover the injections, but not all do. You’ll want to know ahead of time, since the shots are expensive.SourcesUpdate HistorySharePrintSOURCES:American Academy of Family Physicians Family Doctor: "Osteoarthritis of the Knee: Hyaluronic Acid Injections."Karlsson, J.  Rheumatology, 2002.Medina, J.The Journal of Family Practice, August 2006.Elinor Mody, MD, rheumatologist, Brigham and Women's Hospital, Boston.Neustadt, D. Cleveland Clinic Journal of Medicine, October 2006.H. Ralph Schumacher Jr., MD, professor of medicine, University of Pennsylvania Medical School; editor in chief, Journal of Clinical Rheumatology.Wang, C. The Journal of Bone and Joint Surgery, March 2004.SharePrintMore On Osteoarthritis Recommended FEATURED Top doctors in , Find more top doctors on Search Related LinksPoliciesAboutFor Advertisers © 2005 - 2025 WebMD LLC, an company. All rights reserved. WebMD does not provide medical advice, diagnosis or treatment. , Description Hyaluronic acid injection is used to treat knee pain caused by osteoarthritis (OA) in patients who have already been treated with pain relievers (e.g., acetaminophen) and other treatments that did not work well. Hyaluronic acid is similar to a substance that occurs naturally in the joints. It works by acting like a lubricant and shock absorber in the joints and helps the joints to , Hyaluronic acid injections for osteoarthritis and knee pain There are several types of joint (intra-articular) HA injections, which vary in source, structure, molecular weight and the amount needed per treatment (dosing schedule). Source..