What is the best supplement to reduce knee pain in older adults?

Best Supplement for Knee Pain in Older Adults

Based on the most recent and highest quality evidence, no dietary supplement can be recommended for reducing knee pain in older adults—the 2020 American College of Rheumatology/Arthritis Foundation guidelines strongly recommend against glucosamine and chondroitin for knee osteoarthritis, and conditionally recommend against vitamin D, fish oil, turmeric, and ginger extract. 1

Why Supplements Are Not Recommended

The evidence against supplements has strengthened considerably over the past two decades:

Glucosamine and Chondroitin

• Strongly recommended against by the American College of Rheumatology (2020) for knee osteoarthritis 1
• The 2022 American Academy of Orthopaedic Surgeons guidelines note that evidence "does not consistently demonstrate a benefit" and cite lack of reproducibility plus variability between manufacturers with limited FDA oversight 1
• The landmark GAIT trial (1,583 patients) found glucosamine and chondroitin—alone or combined—were not significantly better than placebo in reducing knee pain overall 2
• A 2-year follow-up study showed no treatment achieved clinically important differences in pain or function compared to placebo 3
• Meta-analysis confirms adding glucosamine or glucosamine/chondroitin to exercise provides no additional benefit for pain or function 4
• Publication bias is a major concern: industry-sponsored studies show efficacy while publicly-funded studies with lower risk of bias fail to demonstrate benefits 1

Other Supplements

• Vitamin D: Conditionally recommended against—trials show small effect sizes at best, with pooled data yielding null results 1
• Fish oil: Conditionally recommended against—only one trial exists, which failed to show efficacy 1
• Turmeric and ginger extract: Evaluated by AAOS with evidence showing either minimal improvement or no change 1

Important Caveats

Historical Context

• Older 2003 EULAR guidelines suggested moderate effects for glucosamine (effect size 0.44) and chondroitin (effect size 0.78), but acknowledged potential publication bias 1
• The 2008 NICE guidelines explicitly stated "the use of glucosamine and chondroitin products is not recommended" 1
• The trajectory of evidence has consistently moved away from supplement use as higher-quality, publicly-funded trials emerged

Why Patients Still Use Them

• Glucosamine remains among the most commonly used dietary supplements in the US 1
• Patients often perceive efficacy due to large placebo effects 1
• Toxicity is low, though glucosamine may elevate serum glucose in some patients 1
• The primary barrier is expense since supplements are out-of-pocket costs 1

What Actually Works Instead

First-Line Non-Pharmacological Treatments

• Exercise: Low-impact aerobic activity and quadriceps strengthening show significant effects (effect size 0.52 for pain, 0.46 for disability) 5
• Weight loss: Minimum 5% body weight reduction significantly improves function in patients with BMI ≥25 kg/m² 5
• Combining diet and exercise provides optimal results 5

Pharmacological Options When Needed

• Acetaminophen: First-line oral analgesic for mild-to-moderate pain 5, 6
• Topical NSAIDs: Clinical efficacy with minimal systemic exposure, ideal for older adults with comorbidities 5, 6
• Oral NSAIDs or COX-2 inhibitors: When acetaminophen insufficient, use lowest effective dose for shortest duration with gastroprotection 5
• Intra-articular corticosteroid injections: For acute flares, especially with effusion 5, 6

Critical Clinical Pitfall

Do not recommend supplements based on patient expectations or perceived safety alone—the evidence clearly shows lack of efficacy, and the financial burden to patients is real without meaningful benefit 1