What Is Hyaluronic Acid?
What are the benefits and side effects of hyaluronic acid? Does it really work for knee pain and face lifts?
Andrew Weil, M.D. | February 2, 2023
Hyaluronic acid (HA) is produced naturally in the body. It is a constituent of the synovial fluid that lubricates joints, allowing them to move freely, and also of vitreous humor, the clear, jelly-like substance in the eye. Hyaluronic acid extracted from rooster combs (the Mohawk-like crown on a rooster’s head) or from bacterial cultures is used medically to help relieve knee pain from osteoarthritis when no other treatment has helped. (People with arthritis tend to have lower than normal levels of this substance.) Called “viscosupplementation,” this involves injecting hyaluronic acid, usually in 3 to 5 shots over several weeks. When it works, relief may last as long as two years, although more typically its benefits peak at about three months and then subside.
A 2021 update to guidelines from the American Academy of Orthopaedic Surgeons (AAOS) noted some research that found benefits in the use of HA injections for osteoarthritis of the knee but maintained its position that the treatment is not recommended. The organization had previously noted that HA injections and other procedures are often performed as precursors to knee replacement surgery, which many insurance companies won’t pay for unless patients have tried and failed other treatments.
If you are considering the treatment and are allergic to eggs, be sure to tell your doctor, so you can get bacterial-derived HA and avoid an allergic reaction to the chicken-derived product. There are generally few side effects of treatment. You may have immediate pain, warmth and swelling at the site of the injection, and it is best to avoid standing too long, jogging, or doing heavy lifting for two days following the procedure. Although the injections are expensive, many insurance programs now cover them.
I’m aware that HA injections are also used to reduce facial wrinkles and lines – so-called “liquid facelifts” – to improve appearance prior to a permanent, surgical facelift. As many as three treatments may be needed to get desired results, at a cost of several thousand dollars. Unfortunately, the results typically last only three to 5 months. Risks include allergic reactions or development of red, thickened nodules at the injection sites that can last weeks or months. If you are considering a liquid lift, look for a plastic surgeon qualified to perform the procedure.
I’m also aware of claims that taking HA orally or applying it to the skin can slow aging, but there is no evidence for any of this. Finally, some research suggests that HA can help treat burns and skin wounds, but this remains to be confirmed.
To my knowledge, the best use of hyaluronic acid for the skin is as a topical cream. HA’s ability to retain moisture makes it extremely effective at rehydrating skin. A variety of cosmetic creams and serums containing hyaluronic acid are on the market, including my own line of skin-care products, and are reported to help skin retain moisture.
Andrew Weil, M.D.
Nicholas Bedard et al, “What are the Costs of Knee Osteoarthritis in the Year Prior to Total Knee Arthroplasty.” Paper presented at the 2017 Annual Meeting of the American Academy of Orthopaedic Surgeons, March 14, 2017, San Diego, CA
Originally Published June 2017. Updated February 2023.