What is hyaluronic acid (HA)?

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Last updated: May 23, 2025View editorial policy

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From the Guidelines

Hyaluronic acid injections are not recommended for patients with osteoarthritis of the knee, hip, or first CMC joint due to limited evidence of benefit and potential harm, as stated in the 2020 American College of Rheumatology guideline 1. When considering the use of hyaluronic acid injections, it is essential to weigh the potential benefits against the risks. The 2020 guideline conditionally recommends against the use of hyaluronic acid injections in patients with knee and/or first CMC joint OA and strongly recommends against their use in patients with hip OA.

Some key points to consider:

  • The benefit of hyaluronic acid injections is restricted to studies with higher risk of bias, and when limited to trials with low risk of bias, the effect size approaches zero 1.
  • Many providers may still consider using hyaluronic acid injections when other interventions have failed to adequately control local joint symptoms, but this should be done in the context of shared decision-making and recognizing the limited evidence of benefit.
  • The conditional recommendation against hyaluronic acid injections is not intended to influence insurance coverage decisions.

In contrast to older studies, such as the 2003 EULAR recommendations 1, which suggested a potential benefit of hyaluronic acid injections in knee OA, the more recent guideline 1 provides a more nuanced view of the evidence. Some older studies reported significant reductions in pain and functional improvements with hyaluronic acid injections, but these findings are not supported by more recent, higher-quality research.

Overall, the use of hyaluronic acid injections should be approached with caution, and alternative treatments should be considered first. If hyaluronic acid injections are used, it should be in the context of shared decision-making and with careful consideration of the potential benefits and risks.

From the FDA Drug Label

PRINCIPAL DISPLAY PANEL - 20 mL Bottle Carton Legend® Multi Dose (hyaluronate sodium)Injectable Solution 10 mg/mL For intravenous use in horses only Not for intra-articular use 1 x 20 mL vial CAUTION: Federal law restricts this drug to use by or on the order of a licensed veterinarian. Approved by FDA under NADA # 140-883

The FDA drug label does not answer the question.

From the Research

Hyaluronic Acid Overview

  • Hyaluronic acid (HA) is a well-established treatment for osteoarthritis (OA), particularly in the knee joint 2.
  • HA has been used for over three decades to treat OA, with various preparations and administration methods available 2.
  • The efficacy and safety of HA have been extensively studied, with most research focusing on its use in the knee joint 2, 3.

Efficacy of Hyaluronic Acid

  • Studies have shown that HA can provide significant pain relief and functional improvement in patients with knee OA, with effects lasting up to six months 2, 4.
  • HA has also been found to be effective in treating OA in other joints, including the hip, ankle, and shoulder 3, 5.
  • The combination of HA with other molecules, such as chondroitin sulfate, has been shown to enhance its viscoelastic properties and improve symptoms 4, 5.

Safety of Hyaluronic Acid

  • HA is generally considered safe, with minor side effects such as local pain and swelling being the most common adverse events 2, 6.
  • Severe allergic reactions to HA are extremely rare 2.
  • The use of HA in combination with other treatments, such as corticosteroids or platelet-rich plasma, has been found to be safe and effective 2, 5.

Administration and Dosage

  • HA can be administered via intra-articular injection, with various dosages and frequencies used in different studies 2, 4.
  • The optimal dosage and frequency of HA administration are still being researched, with some studies suggesting that a single injection can be effective 5.
  • The use of HA in combination with other treatments may require adjustments to the dosage and frequency of administration 2, 4.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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