What does the research show about glucosamine and chondroitin?

Glucosamine and chondroitin

A network meta-analysis of 10 large trials found pain differences from placebo smaller than the threshold patients notice, and no change in joint space. Industry-independent trials showed smaller effects than commercially funded ones. A Cochrane review of chondroitin found modest pain gains from lower-quality trials. Adverse events matched placebo. Warfarin users have reported raised INR.

Add to Bio HackChecked 2026-11-09

Status: Dietary supplements in the US. Also sold as prescription drugs in some countries.
Also called: glucosamine sulfate, glucosamine hydrochloride, crystalline glucosamine sulfate, Rotta glucosamine, chondroitin sulfate, Cosamin DS, joint supplements
Taken for: joint pain, knee osteoarthritis, hip osteoarthritis, cartilage, joint health, stiffness, injury recovery

Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on

Shown to help2

ModerateShown to lower pain about 10% in trials under 6 months in people with osteoarthritis, mostly of the knee. Reviews disagree on whether this is meaningful.Very common
LimitedLimited evidence: habitual glucosamine use was linked to about 15% fewer cardiovascular events in UK adults. No trial has tested this.

Reported risks4

ModerateMixed results: one 90-day trial found no HbA1c change in type 2 diabetes, while 4 of 11 studies reported lower insulin sensitivity or higher glucose.How often is not known
LimitedCase reports: glucosamine products drew the most supplement reports in Singapore, mainly rash, itching, hives and swelling.How often is not known
LimitedCase reports: INR rose in people on warfarin taking glucosamine, with one brain bleed among 20 FDA reports.How often is not known
LimitedLimited evidence: most of 25 European supplements held less glucosamine and chondroitin than declared, by up to 60%, and all had keratan sulfate contamination.How often is not known

What people take it for, and what was found

Shown to help2

ModerateVery common

Chondroitin and pain in shorter trials

Shown to lower pain about 10% in trials under 6 months in people with osteoarthritis, mostly of the knee. Reviews disagree on whether this is meaningful.

The numbers and sources

How common: Very common: more than 1 in 10 people.
Effect: Across 43 RCTs, chondroitin lowered pain by an absolute 10% (95% CI 6 to 15%) in studies under 6 months, with I² 70% and low-quality evidence. A 20% reduction in knee pain was reached by 53 per 100 on chondroitin and 47 per 100 on placebo (RR 1.12, 95% CI 1.01 to 1.24, 2 trials, high-quality evidence) [4].
Population: 4,962 participants on chondroitin and 4,148 controls, mostly knee osteoarthritis, 1 month to 3 years [4].
Sources: [4]
Caveats: This review and the network meta-analysis disagree on whether chondroitin's pain effect is clinically meaningful [1][4]. High heterogeneity was not explained by bias or sample size [4].

Limited

Cardiovascular events

Limited evidence: habitual glucosamine use was linked to about 15% fewer cardiovascular events in UK adults. No trial has tested this.

The numbers and sources

Effect: Among 466,039 UK Biobank participants followed a median 7 years, habitual glucosamine use was associated with fewer cardiovascular events (HR 0.85, 95% CI 0.80 to 0.90) and cardiovascular deaths (HR 0.78) [6].
Population: UK adults without cardiovascular disease at baseline [6].
Sources: [6]
Caveats: Observational. No randomized trial has tested this.

Mixed results2

Moderate

Glucosamine product type

Mixed results: trials of the Rotta preparation showed larger pain relief, while other preparations and well-concealed trials found no benefit.

The numbers and sources

Effect: Across 20 RCTs, glucosamine improved pain (SMD -0.61, 95% CI -0.95 to -0.28), but analyses limited to 8 trials with adequate allocation concealment found no benefit. Trials of the Rotta preparation showed pain SMD -1.31, while non-Rotta preparations showed SMD -0.15 (95% CI -0.35 to 0.05) [5].
Population: 2,570 patients in 20 RCTs [5].
Sources: [5]
Caveats: WOMAC pain, function and stiffness did not differ from placebo in this review. The 2005 search predates the large independent trials [2][3].

Moderate

Joint space narrowing

Mixed results: one review found minute differences in joint space width, while others found slightly less narrowing with chondroitin or Rotta glucosamine.

The numbers and sources

Effect: Differences in joint space width were minute, with credible intervals overlapping zero for all three preparations [1]. In 2 trials, loss of minimum joint space width was 4.7% less with chondroitin (95% CI 1.6% to 7.8%) [4]. Two Rotta glucosamine trials found slower radiological progression over 3 years (SMD 0.24) [5].
Population: Adults with knee osteoarthritis followed up to 3 years [1][4][5].
Sources: [1], [4], [5]
Caveats: Reviews disagree. Joint space width is a structural measure and was not tied to symptoms in these abstracts.

Not shown to help1

Strong

Knee and hip osteoarthritis pain

Not shown to lower osteoarthritis pain by a clinically important amount: about 0.3 to 0.5 cm on a 10 cm scale, and independent trials found no difference.

The numbers and sources

Effect: Across 10 trials (3,803 patients), pain on a 10 cm scale differed from placebo by -0.4 cm for glucosamine (95% credible interval -0.7 to -0.1), -0.3 cm for chondroitin and -0.5 cm for the combination. None reached the prespecified minimal clinically important difference of -0.9 cm [1]. In 1,583 patients over 24 weeks, response rates did not differ significantly from placebo (60.1%): 3.9 points higher with glucosamine, 5.3 with chondroitin and 6.5 with both. Celecoxib was 10.0 points higher [2]. Individual patient data from 5 industry-independent trials (1,625 people) found glucosamine no different from placebo at 3 and 24 months, in every predefined subgroup [3].
Population: Adults with knee or hip osteoarthritis [1][2][3].
Sources: [1], [2], [3]
Caveats: Industry-independent trials showed smaller effects than commercially funded trials (P = 0.02 for interaction) [1]. In GAIT, an exploratory subgroup with moderate to severe pain responded more to the combination (79.2% versus 54.3%) [2].

Doses studied

GAIT used 1,500 mg glucosamine and 1,200 mg chondroitin sulfate a day, alone or together, for 24 weeks [2]. A diabetes trial used the same combination for 90 days [7]. Chondroitin trials ran from 1 month to 3 years [4].

Risks

Reported risks3

LimitedHow often is not known

Allergic skin reactions in adverse event reports

Case reports: glucosamine products drew the most supplement reports in Singapore, mainly rash, itching, hives and swelling.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Of 727 adverse event reports for complementary health products sent to Singapore's Health Sciences Authority from 2017 to 2023, health supplements made up 68%, and glucosamine-containing products accounted for the most reports, mainly skin and hypersensitivity reactions such as rash, itching, hives and swelling [8].
Population: National spontaneous reporting data from Singapore [8].
Sources: [8]
Caveats: Spontaneous reports cannot give a rate, and wide use raises report counts. The authors note glucosamine is typically derived from shellfish [8].

LimitedHow often is not known

Interaction with warfarin

Case reports: INR rose in people on warfarin taking glucosamine, with one brain bleed among 20 FDA reports.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: A 71-year-old man on stable warfarin had INR rise from 2.3 to 3.9 after tripling his glucosamine-chondroitin dose, and to 4.7 after a partial reduction. The FDA MedWatch database held 20 reports of altered coagulation with glucosamine or glucosamine-chondroitin and warfarin, one an intraventricular bleed. The WHO database held 21 reports of raised INR, 17 of which resolved when glucosamine was stopped [9].
Population: Case report and pharmacovigilance databases [9].
Sources: [9]
Caveats: Spontaneous reports cannot give a rate.

LimitedHow often is not known

Label content

Limited evidence: most of 25 European supplements held less glucosamine and chondroitin than declared, by up to 60%, and all had keratan sulfate contamination.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Of 25 food supplements from 8 European countries, over 19 contained less chondroitin sulfate and glucosamine than declared, by up to 60.3%. All contained keratan sulfate contamination, up to 47.1% [11].
Population: Product testing [11].
Sources: [11]
Caveats: European products only. Two pharmaceutical products were tested alongside for comparison.

Mixed results1

ModerateHow often is not known

Blood sugar

Mixed results: one 90-day trial found no HbA1c change in type 2 diabetes, while 4 of 11 studies reported lower insulin sensitivity or higher glucose.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: In a 90-day RCT in people with type 2 diabetes, 1,500 mg glucosamine with 1,200 mg chondroitin did not change HbA1c compared with placebo [7]. A systematic review of 11 studies found 4 reporting lower insulin sensitivity or higher fasting glucose. Studies including people with impaired glucose tolerance or insulin resistance were more likely to detect an effect [10].
Population: Adults with well-controlled type 2 diabetes [7]; mixed human studies [10].
Sources: [7], [10]
Caveats: The review calls the evidence mixed [10]. The diabetes trial tested one branded product, Cosamin DS from Nutramax Laboratories [7].

Checked, no increase found1

Strong

Adverse events in trials

Adverse events were about as common as on placebo for glucosamine and chondroitin in osteoarthritis trials.

The numbers and sources

How common: How often is not known: the sources give no rate.
Effect: Glucosamine and placebo had similar numbers of people reporting adverse reactions (RR 0.97, 95% CI 0.88 to 1.08) [5]. Chondroitin did not raise adverse events or withdrawals, and serious adverse events were lower than placebo (Peto OR 0.40, 95% CI 0.19 to 0.82, 6 trials) [4]. In GAIT, adverse events were mild, infrequent and evenly distributed [2].
Population: Osteoarthritis trial participants [2][4][5].
Sources: [2], [4], [5]
Caveats: Adverse event reporting was limited in some chondroitin trials [4].

Claims tested and not found

That glucosamine relieves osteoarthritis pain. Individual patient data from 5 independent trials found no difference from placebo at 3 or 24 months [3].
That glucosamine and chondroitin slow joint space loss. Differences were minute, with credible intervals overlapping zero [1].

Sources

Wandel S, Juni P, Tendal B, et al. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis. BMJ. 2010. https://doi.org/10.1136/bmj.c4675
Clegg DO, Reda DJ, Harris CL, et al. Glucosamine, Chondroitin Sulfate, and the Two in Combination for Painful Knee Osteoarthritis. New England Journal of Medicine. 2006. https://doi.org/10.1056/NEJMoa052771
Runhaar J, Rozendaal RM, van Middelkoop M, et al. Subgroup analyses of the effectiveness of oral glucosamine for knee and hip osteoarthritis: a systematic review and individual patient data meta-analysis from the OA trial bank. Annals of the Rheumatic Diseases. 2017. https://doi.org/10.1136/annrheumdis-2017-211149
Singh JA, Noorbaloochi S, MacDonald R, et al. Chondroitin for osteoarthritis. Cochrane Database of Systematic Reviews. 2015. https://doi.org/10.1002/14651858.CD005614.pub2
Towheed T, Maxwell L, Anastassiades TP, et al. Glucosamine therapy for treating osteoarthritis. Cochrane Database of Systematic Reviews. 2005. https://doi.org/10.1002/14651858.CD002946.pub2
Ma H, Li X, Sun D, et al. Association of habitual glucosamine use with risk of cardiovascular disease: prospective study in UK Biobank. BMJ. 2019. https://doi.org/10.1136/bmj.l1628
Scroggie DA, Albright A, Harris MD. The Effect of Glucosamine-Chondroitin Supplementation on Glycosylated Hemoglobin Levels in Patients With Type 2 Diabetes Mellitus. Archives of Internal Medicine. 2003. https://doi.org/10.1001/archinte.163.13.1587
Quek YL, Zeng Y, Ge X, et al. Analysis of adverse event reports associated with complementary health products in Singapore from 2017 to 2023. Frontiers in Medicine. 2026. https://doi.org/10.3389/fmed.2026.1872698
Knudsen JF, Sokol GH. Potential Glucosamine-Warfarin Interaction Resulting in Increased International Normalized Ratio: Case Report and Review of the Literature and MedWatch Database. Pharmacotherapy. 2008. https://doi.org/10.1592/phco.28.4.540
Dostrovsky N, Towheed T, Hudson R, et al. The effect of glucosamine on glucose metabolism in humans: a systematic review of the literature. Osteoarthritis and Cartilage. 2011. https://doi.org/10.1016/j.joca.2011.01.007
Restaino OF, Finamore R, Stellavato A, et al. European chondroitin sulfate and glucosamine food supplements: A systematic quality and quantity assessment compared to pharmaceuticals. Carbohydrate Polymers. 2019. https://doi.org/10.1016/j.carbpol.2019.114984

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