Glucosamine and chondroitin for joint pain: what the evidence says

Glucosamine and chondroitin are natural components of cartilage, the cushioning tissue at the ends of bones. Supplements are made either from shellfish shells or from animal cartilage, or produced synthetically, and are taken by mouth as tablets, capsules or powders, alone or together.

The reasoning behind their use is that supplying the building blocks of cartilage might slow its breakdown or ease pain in osteoarthritis. The body does not simply route a swallowed supplement to the joint, though, and the question has been tested in clinical trials rather than assumed.

NCCIH summarises the evidence as mixed. It says that despite extensive research it is still uncertain whether glucosamine and chondroitin make a meaningful difference to symptoms or joint structure. Some large NIH-sponsored studies found little or no pain relief for knee osteoarthritis, while other studies suggested a benefit.

On chondroitin alone, NCCIH reports inconsistent results, but in general the largest, highest-quality studies have not shown an effect. Where changes in joint structure were seen with chondroitin or the combination, they were often too small to help patients meaningfully. The American College of Rheumatology, as quoted by NCCIH, conditionally recommends against using glucosamine and chondroitin for knee or hip osteoarthritis.

The NHS osteoarthritis page states that GPs no longer prescribe chondroitin and glucosamine on the NHS because there is no strong evidence that they are effective as a treatment. It adds that NICE recommends they should not routinely be offered on the NHS, because of cost and lack of proven efficacy.

This is guidance on prescribing, not a ban. People can still buy these products as food supplements, and some feel better taking them. Because pain from osteoarthritis rises and falls naturally and responds strongly to expectation, an individual improvement does not prove the product caused it. A fair approach is to treat any trial as a time-limited experiment and stop if there is no clear gain.

NCCIH says overall studies have not shown other serious side effects, but warns that glucosamine and chondroitin may interact with warfarin. Anyone on warfarin or another blood thinner should discuss it with their prescriber or anticoagulant clinic, because a change in blood-thinning effect can matter.

Because many glucosamine products are derived from shellfish, people with a shellfish allergy should read labels carefully and ask a pharmacist, as the NCCIH page does not address this point. People who take medicines for diabetes or who are pregnant or breastfeeding should also ask for advice before trying a joint supplement.

NCCIH also records that the US regulator has warned about tainted arthritis supplements containing hidden prescription drugs. That is a reason to be wary of products promising rapid, dramatic pain relief, and to buy only from reputable pharmacies and retailers.

The NHS describes exercise as one of the most important treatments, with weight management where relevant. Paracetamol may help for short-term relief, though many find it does not work very well. Anti-inflammatory tablets or gels are described as particularly effective for knees and hands, and capsaicin cream can be tried on the hands or knees, which may take up to a month for full effect.

Hot and cold packs, walking aids, splints and supportive footwear, and manual therapy through physiotherapy are also listed. Steroid injections are offered when other treatments fail and can ease pain for several weeks or months, and surgery such as joint replacement is considered for severe cases.

• Regular, graded exercise and strengthening.

• Weight management where it applies.

• Pain relief chosen with a pharmacist or GP.

• Physiotherapy, aids and supportive footwear.

If you decide to try one, pick a single product, note your pain and function before you start, and review after a few months. Keep taking your proven treatments, tell your pharmacist and GP about it, and do not stop prescribed medicines because a supplement seems to help.

See a GP if joint pain is worsening, if a joint is hot, red and swollen, or if night pain or stiffness lasting over half an hour in the morning develops, because other conditions can look like osteoarthritis. Sudden severe joint pain with fever is an emergency: use NHS 111 or A&E.