Is glucosamine or chondroitin effective for treating knee osteoarthritis?

From the Guidelines

Glucosamine and chondroitin have limited effectiveness for treating knee osteoarthritis, and their use should be considered on a case-by-case basis, taking into account individual patient characteristics and preferences, as recommended by the 2019 American College of Rheumatology guideline for the management of osteoarthritis of the hand, hip, and knee 1. The evidence for the effectiveness of glucosamine and chondroitin in treating knee osteoarthritis is mixed, with some studies showing modest benefits and others showing no significant effects.

• The 2019 American College of Rheumatology guideline for the management of osteoarthritis of the hand, hip, and knee recommends considering glucosamine and chondroitin as part of a comprehensive treatment plan, but notes that the evidence for their effectiveness is limited 1.
• A 2007 study published in the Annals of the Rheumatic Diseases found that glucosamine and chondroitin had small but statistically significant effects on pain relief and functional improvement in patients with knee osteoarthritis, but noted that the evidence was not strong enough to support their use as a first-line treatment 1.
• A 2003 study published in the Annals of the Rheumatic Diseases found that glucosamine and chondroitin had moderate to large effects on pain and disability in osteoarthritis, but noted that the evidence was limited by publication bias and the lack of standardization in the studies 1. Overall, while glucosamine and chondroitin may have some benefits for patients with knee osteoarthritis, their use should be considered in the context of a comprehensive treatment plan that includes weight management, exercise, and conventional pain management, and patients should discuss their use with their healthcare provider before starting, especially if they have diabetes or are taking blood thinners.
• Typical supplementation involves glucosamine sulfate 1500mg daily and chondroitin sulfate 800-1200mg daily, often taken together.
• These supplements are generally safe with minimal side effects, primarily mild gastrointestinal discomfort.
• They work theoretically by providing building blocks for cartilage repair and potentially reducing inflammation, though the actual mechanism remains unclear.
• Results vary significantly between individuals, and benefits may take 2-3 months to appear if they occur at all.

From the Research

Effectiveness of Glucosamine and Chondroitin for Knee Osteoarthritis

• The effectiveness of glucosamine and chondroitin for treating knee osteoarthritis is a topic of ongoing debate, with some studies suggesting a potential benefit and others finding no significant difference compared to placebo 2, 3, 4.
• A study published in 2008 found that glucosamine and chondroitin sulfate, alone or in combination, did not significantly reduce the progression of knee osteoarthritis compared to placebo 2.
• Another study published in 2006 found that glucosamine and chondroitin sulfate, alone or in combination, were not significantly better than placebo in reducing knee pain, although the combination of both supplements showed a trend towards improvement in patients with moderate-to-severe pain 3.
• A review published in 2017 found that the current evidence-based information regarding the administration of glucosamine and chondroitin for the treatment of knee or hip osteoarthritis is limited, and the effect sizes are generally small and probably not clinically relevant 4.

Clinical Efficacy and Safety

• A study published in 2012 suggested that glucosamine and chondroitin sulfate have the potential to provide pain-relieving benefits as well as possibly decrease the effects of joint space narrowing, although the evidence is not conclusive 5.
• A long-term observational study published in 2023 found that the combination of glucosamine and chondroitin sulfate was associated with decreased pain, reduced concomitant NSAID therapy, improved joint function, and quality of life in patients with knee and hip osteoarthritis 6.
• The safety profile of glucosamine and chondroitin sulfate is generally considered to be good, with few adverse events reported in clinical trials 3, 6.

Key Findings

• The current evidence suggests that glucosamine and chondroitin sulfate may have a small, potentially clinically relevant effect on knee osteoarthritis symptoms, particularly in patients with moderate-to-severe pain 3, 6.
• However, the evidence is not conclusive, and more high-quality studies are needed to fully understand the effectiveness of these supplements for treating knee osteoarthritis 2, 4.