NOW Foods Glucosamine & Chondroitin Extra Strength

Glucosamine· evidence: Limited

Glucosamine is a building block of cartilage. In supplements it comes as glucosamine sulphate or glucosamine hydrochloride, usually made from crab and shrimp shells, or from fermented corn in vegan versions. N-acetyl glucosamine is a related form with even less research behind it.

It has been studied a lot, and the results are disappointing. Large independent trials, such as the US GAIT trial, and a big review of the research found little or no difference from a dummy pill for most people. Some earlier trials using one branded glucosamine sulphate looked better, but many of those were funded by the maker. NICE does not recommend glucosamine on the NHS, and EFSA rejected a claim that it helps keep joints healthy.

There is no authorised health claim for glucosamine, so we make no claims about what it does. If you want to try it, the dose used in studies is 1,500 mg of glucosamine sulphate a day, and it is fair to stop after about three months if you notice no difference.

Typical dose: Studies used 1,500 mg of glucosamine sulphate a day

Safety: Most glucosamine is made from shellfish: avoid unless the label says it is from a non-shellfish source if you have a shellfish allergy. Glucosamine may strengthen the effect of warfarin, so speak to your GP or pharmacist first if you take warfarin or another blood thinner. Speak to your GP first if you have diabetes, asthma or glaucoma, or are pregnant or breastfeeding. Can cause mild stomach upset.

Research we looked at:
Clegg DO et al. (2006). Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med 354:795–808.
Wandel S et al. (2010). Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ 341:c4675.
NICE (2022). Osteoarthritis in over 16s: diagnosis and management. NICE guideline NG226.
EFSA NDA Panel (2009). Scientific opinion on the substantiation of health claims related to glucosamine alone or in combination with chondroitin sulphate and maintenance of joints. EFSA Journal 7(9):1264.

Chondroitin· evidence: Limited

Chondroitin sulphate is another natural part of cartilage. In supplements it usually comes from cow, pig, chicken or shark cartilage, and a few vegan versions are made by fermentation. It is often paired with glucosamine.

The research is mixed. Large independent trials found little or no benefit over a dummy pill for most people, while some smaller and maker-funded trials looked more positive, and the quality of chondroitin in supplements varies. EFSA rejected a claim that it helps keep joints healthy, and NICE does not recommend it on the NHS.

There is no authorised health claim for chondroitin, so we make no claims about what it does. Studies have mostly used 800–1,200 mg a day; many combination products contain far less.

Typical dose: Studies mostly used 800–1,200 mg a day

Safety: Usually made from animal cartilage, so not suitable for vegetarians unless stated. May add to the effect of warfarin and other blood thinners: speak to your GP or pharmacist first if you take them. Not recommended in pregnancy or breastfeeding without advice.

Research we looked at:
Clegg DO et al. (2006). Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med 354:795–808.
Singh JA et al. (2015). Chondroitin for osteoarthritis. Cochrane Database Syst Rev (1):CD005614.
Wandel S et al. (2010). Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ 341:c4675.
NICE (2022). Osteoarthritis in over 16s: diagnosis and management. NICE guideline NG226.

Cost per daily dose lets you compare packs of different sizes fairly.Worked out from our current prices.