Topic 15 · Everything else
Nutritional Supplements
Modest pain benefit at best. Will not regenerate cartilage.
2025 Systematic Review
→ Glucosamine, chondroitin, collagen = cartilage building blocks taken as pills/powders. Gives body extra raw materials. Research is mixed - may help pain modestly. Generally safe but unlikely to regenerate destroyed cartilage.
A comprehensive 2025 review of 146 studies on glucosamine and chondroitin [108]:
- Over 90% of efficacy studies reported positive outcomes
- Most safety studies indicated minimal or no adverse effects
- Type II collagen peptides showed consistent efficacy
- Often combined with MSM, curcuminoids, and HA
2025 RCT Results
A 12-week randomized controlled trial (52 participants) on combination supplements [109]:
Important Caveats
NIH/NCCIH notes mixed evidence [110]:
- Studies have had inconsistent results
- Expert evaluations have reached conflicting conclusions
- A 2024 meta-analysis found glucosamine/chondroitin did not significantly reduce joint pain or prevent joint space narrowing [111]
Bottom line: Generally safe to try for 3-6 months. May provide modest pain relief. Not a substitute for proper medical treatment.
Added August 13, 2026 — betaine (trimethylglycine): a preclinical mechanism, not a recommendation
A Nanjing group reported that betaine — an over-the-counter supplement — downregulates the fibrosis gene RARRES1 and steers cartilage repair toward hyaline rather than fibrotic tissue, in cell and animal models only [415]. It is carried on the emerging-therapies page (topic 23), not here, for a reason: there is no human joint trial, no dosing evidence, and no basis for adding it to a supplement regimen. It appears on this page only so that a search for it lands on the honest version rather than a sales pitch.