Hyaluronic Acid
Hyaluronic acid injections are used to treat osteoarthritic knee pain. It is recommended if patients want to postpone joint replacement or if other treatment options are not effective, such as anti-inflammatory medications, acetaminophen, physical therapy, weight loss, and corticosteroid injections.
Hyaluronan is a substance that is a lubricant and shock absorber and helps the joint to move smoothly. In an arthritic knee, the quality and quantity of hyaluronan in the joint is reduced. Your doctor can inject hyaluronic acid to supplement the naturally occurring hyaluronic acid which may provide temporary pain relief. The injections may help with the pain but not reverse or prevent damage.
How To Take It
Hyaluronic acid is injected into the knee joint in the doctor’s office. There are many different brands of hyaluronic acid. No brand has been shown to work better or worse than another. Let your doctor know if you have a chicken or egg allergy, as some brands are formulated using animal proteins. The injections are given weekly for one to five weeks.
Your doctor will check your progress to see if it is working and if you should continue to receive it. The response is variable. For patients who have pain relief, it may take a few days to several weeks to notice improvement. The length of pain relief is variable. Some patients may have pain relief for a few months. If the injections are helpful, then they can be repeated in 6 months.
Side Effects
The most common side effects include local reactions with pain, warmth, swelling, and difficulty moving the knee immediately after the injection. These symptoms are short lived and applying ice helps. You should not strain your knee with prolonged standing or participate in activities like running or heavy lifting for one to two days after receiving hyaluronic acid. Call your rheumatology provider if the pain or swelling in the knee persists or becomes worse.
Other less common side effects include bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, joint infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, ulceration and warmth at the injection site. If a reaction develops to a particular brand, it may be helpful to try a different brand if future treatments are planned.
Tell Your Rheumatology Provider
You should notify your rheumatology provider if you experience side effects or allergic reactions. Tell your provider if you experience bleeding problems. If you are pregnant or breastfeeding, let your doctor know before starting this medication as safety in pregnancy and breastfeeding has not been determined. If you develop swelling or worsening pain in the knee, tell your rheumatology provider.
Updated March 2025 by Rebecca Fitzpatrick, MD, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.
This information is provided for general education only. Individuals should consult a qualified healthcare provider for professional medical advice, diagnosis, and treatment of a medical or health condition.