“Glucosamine or chondroitin rebuild worn cartilage.”
Glucosamine and chondroitin have not been shown to rebuild worn cartilage.
Glucosamine and chondroitin do not repair a worn joint. Any pain relief they give is small for most people, and it is a separate question from rebuilding cartilage.
Do not buy glucosamine or chondroitin expecting to regrow cartilage. If joint pain is a problem, ask your clinician about treatments with stronger evidence.
Safety note: Glucosamine and chondroitin have been linked to a higher risk of bleeding in people who take the blood thinner warfarin. Glucosamine may raise blood sugar in some people. Little is known about safety during pregnancy or breastfeeding.
Talk to a healthcare professional if: a joint is painful, swollen or injured, or you take warfarin, have diabetes, or are pregnant or breastfeeding.
Several large, multi-year trials have looked for structural effects. None show worn cartilage regrowing, and joint-space results are small and inconsistent; slower narrowing in some trials is a different outcome from rebuilding cartilage, so it is not a grain of truth.
Glucosamine and chondroitin have not been shown to rebuild worn cartilage. The studies measured how fast the space inside the joint narrows on X-rays, not whether cartilage grew back, and even on that measure results are small and conflicting.
Some trials found slightly less joint-space narrowing on X-rays, but other large two-year trials found no difference. Two trials of one prescription glucosamine product slowed narrowing over 3 years, and two 2-year chondroitin trials found less narrowing. A US trial of 572 people found no difference from placebo for glucosamine, chondroitin or both after 2 years, and an Australian trial of 605 people found less narrowing only with the combination. A pooled analysis of the largest trials found the joint-space differences were tiny and could be due to chance. Slower narrowing, where it occurs, is a different outcome: it is not the same as damaged cartilage growing back.
- National Center for Complementary and Integrative Health. Glucosamine and Chondroitin for Osteoarthritis: What You Need To Know. Last updated October 2023
- Wandel S, Jüni P, Tendal B, Nüesch E, Villiger PM, Welton NJ, Reichenbach S, Trelle S. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ. 2010;341:c4675. DOI: 10.1136/bmj.c4675. PMID: 20847017
- Singh JA, Noorbaloochi S, MacDonald R, Maxwell LJ. Chondroitin for osteoarthritis. Cochrane Database of Systematic Reviews. 2015;(1):CD005614. DOI: 10.1002/14651858.CD005614.pub2
- Towheed T, Maxwell L, Anastassiades TP, Shea B, Houpt J, Welch V, Hochberg MC, Wells GA. Glucosamine therapy for treating osteoarthritis. Cochrane Database of Systematic Reviews. 2005;(2):CD002946. DOI: 10.1002/14651858.CD002946.pub2
- Rabade A, Viswanatha GL, Nandakumar K, Kishore A. Evaluation of efficacy and safety of glucosamine sulfate, chondroitin sulfate, and their combination regimen in the management of knee osteoarthritis: a systematic review and meta-analysis. Inflammopharmacology. 2024;32(3):1759-1775. DOI: 10.1007/s10787-024-01460-9. PMID: 38581640