Supplement · graded by use, two uses
Chondroitin Sulfate
Osteoarthritis pain and function, chondroitin as generally sold.
Grade C: human trials exist, but they are small, mixed or not yet repeated. This is not a finding that it does not work. How to read a grade →
Chondroitin is a building block of joint cartilage. It is sold for arthritis pain. The large studies of chondroitin as it is usually sold found no benefit or mixed results. When it was combined with glucosamine, people did no better than those taking a dummy pill.
The C belongs to one of the two uses graded on this record. The other one carries its own letter.
As studied, and the trials
The large, well-concealed trials are null: Clegg et al. (N Engl J Med, 2006; PMID 16495392), Reichenbach et al. (Ann Intern Med, 2007; PMID 17438317), Wandel et al. (BMJ, 2010; PMID 20847017). Singh et al. (Cochrane, 2015; PMID 25629804) found a small short-term benefit of low quality that became uncertain in the best trials, and Honvo et al. (Adv Ther, 2019; PMID 30879253) found non-pharmaceutical preparations did not reduce pain. Rabade et al. (Inflammopharmacology, 2024; PMID 38581640) was positive. Mixed: C.
As studied, and the trials
Roman-Blas et al. (Arthritis Rheumatol, 2017; PMID 27477804): the combination did worse than placebo An inactive substitute made to look like the real treatment, so participants cannot tell which one they received. on pain. Rabade et al. (Inflammopharmacology, 2024; PMID 38581640): the combination improved neither pain nor function across 3 trials. GAIT (Clegg et al., N Engl J Med, 2006; PMID 16495392) was not significant overall. C, close to D.
Read the grade that matches your goal. How EBL grades by use →
- Dose studied
- 800–1,200 mg/day
- Form graded
- Chondroitin sulfate
- Evidence behind the C
- PMID 16495392 →PMID 17438317 →PMID 20847017 →PMID 25629804 →
A letter describes the human evidence, not the product, the manufacturer, or the ingredient's worth.
See the full evidence record →Chondroitin sulfate as generally sold, for osteoarthritis pain and function, graded on human trial evidence.
As studied: dose, form, population and duration for every use
A grade describes the intervention that was tested. Where the product on the shelf differs from it, this says so.
How this letter has changed · latest: October 2026 · Corrected
The record said Rabade et al. (Inflammopharmacology, 2024; PMID 38581640) and Gregori et al. (JAMA, 2018; PMID 30575881) found small benefits from chondroitin, often with glucosamine. Gregori found no long-term pain benefit for chondroitin, and Rabade found the combination with glucosamine improved neither pain nor function. A PubMed search for every randomized trial and pooled analysis found the B rests on one preparation: pharmaceutical-grade chondroitin sulfate at 800 mg a day (Reginster et al., Ann Rheum Dis, 2017; PMID 28533290; Honvo et al., Adv Ther, 2019; PMID 30879253). Chondroitin as generally sold, and the combination with glucosamine, are graded C.PMID 38581640 PMID 30575881 PMID 28533290 PMID 30879253
Earlier today the B was scoped to pharmaceutical-grade chondroitin sulfate at 800 mg a day, the preparation tested by Reginster et al. (Ann Rheum Dis, 2017; PMID 28533290) and pooled by Honvo et al. (Adv Ther, 2019; PMID 30879253). A check found it is a registered medicine in several European countries and is not sold in the United States. A letter readers cannot act on is not published, so the record now carries the letter for chondroitin as generally sold, whose large independent trials, including GAIT (Clegg et al., N Engl J Med, 2006; PMID 16495392), were null or mixed: C.PMID 28533290 PMID 30879253 PMID 16495392
Every change to a letter on this site is dated and published. The full evidence log →
Commercial disclosure
EBL earns no commission on any supplement it grades. A purchase made through the dispensary link below pays EBL nothing, the practitioner discount goes to you in full. The dispensary is Fullscript, a practitioner dispensary, and many of the professional-grade brands in it are sold mainly through practitioners rather than in health food stores. Grades are assigned by published rubric before any commercial relationship exists and are never influenced by one. Full disclosure.
No dose is published here. This record carries no authored dose, because the cited trials do not converge on a single figure. Each trial cited on this page states the dose it used, and EBL has not turned those into a recommendation.
Standardized extracts/forms were used in the cited trials; product quality varies.
The cited reviews pool trials and do not report when doses were taken (PMID 38581640, PMID 30575881).
Checked against the full report for 1 of the 2 cited studies, and the published summary for the rest. What the cited trials did, not a schedule. Every supplement, by trial timing →
Raised bleeding risk. Separation from surgery is the usual clinical margin.
Warfarin: published case reports and pharmacovigilance records describe INR rising on glucosamine-chondroitin, sometimes enough to matter. There is no controlled trial establishing the size of the effect, so the caution is a monitoring one rather than a quantified one.
Glucosamine-chondroitin and warfarin. Case reports and pharmacovigilance records describe INR rising when glucosamine-chondroitin is added to warfarin. No controlled trial has quantified the effect. Knudsen and Sokol (Pharmacotherapy, 2008; PMID 18363538): case report plus a review of the literature and MedWatch reports of a potential glucosamine-warfarin interaction raising INR. Rozenfeld et al. (American Journal of Health-System Pharmacy, 2004; PMID 14986566): possible augmentation of warfarin effect by glucosamine-chondroitin.
Joint pain on the WOMAC or VAS scale at baseline, 8 weeks, and 16 weeks: the GAIT trial used WOMAC as the primary endpoint The one outcome a trial names in advance as its main test. Results on other outcomes carry less weight. and showed benefit primarily in moderate-to-severe knee OA. Range of motion and stair-climbing time are practical functional secondary endpoints An outcome a trial also measures but did not choose as its main test.. Chondroitin requires 8-12 weeks before a meaningful response is detectable; do not judge efficacy at 4 weeks.
Primary evidenceNine papers, each linked to its PubMed record.
Reginster et al. (Annals of the Rheumatic Diseases, 2017; PMID 28533290), CONCEPT: 604 people with knee osteoarthritis, double-blind, pharmaceutical-grade chondroitin sulfate 800 mg a day, celecoxib or placebo for 182 days; chondroitin beat placebo on pain and the Lequesne index and matched celecoxib. Honvo et al. (Advances in Therapy, 2019; PMID 30879253): in low risk of bias trials, the pharmaceutical-grade preparation reduced pain and improved function and other preparations did not. The two papers come from the same research network and the preparation is one manufacturer's. That preparation is a registered medicine in several European countries and is not sold in the United States, so no letter on this page rests on it. For chondroitin as generally sold the large trials are null: Clegg et al. (New England Journal of Medicine, 2006; PMID 16495392), GAIT, 1,583 patients; Reichenbach et al. (Annals of Internal Medicine, 2007; PMID 17438317), effect near zero in the 3 large trials; Wandel et al. (BMJ, 2010; PMID 20847017), inside the minimal important difference; Singh et al. (Cochrane Database of Systematic Reviews A review that searches for every study on a question using a method set in advance, then assesses them together., 2015; PMID 25629804), a small low-quality short-term benefit. Gregori et al. (JAMA, 2018; PMID 30575881) found no long-term pain benefit for chondroitin, only less joint space narrowing. Rabade et al. (Inflammopharmacology, 2024; PMID 38581640) found chondroitin alone helped and the combination with glucosamine did not; Roman-Blas et al. (Arthritis and Rheumatology, 2017; PMID 27477804) found the combination no better than placebo. Pain and function are self-reported. Chondroitin as sold to readers here is graded C.
Educational use only · Not medical advice · Starting, stopping or changing any supplement or medication is a decision for your physician
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. The grade on this page describes the strength of published human trial evidence in the populations studied. It is not a recommendation for any individual and is not medical advice. Starting, stopping or changing any supplement or medication is a decision for your physician.
Who responds: this record's trial reading reports no subgroup that identifies who responds.
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How this is enforced
That is not a promise, it is a build condition. Two checks run on every deploy: one refuses to publish if a commission is claimed on anything graded, the other refuses if a page names a commercial relationship that is not declared in the register. If either fails, this page does not go live. You can read how the checks work, and what they do not cover, on the evidence integrity page.
How EBL searched for the trials (1 search)
The search that was run, what it returned, and what was left out and why, so the absence of evidence can be checked as well as its presence.
chondroitin[tiab] AND osteoarthritis[tiab] AND (pain[tiab] OR function[tiab] OR WOMAC[tiab]) AND (meta-analysis[pt] OR randomized controlled trial[pt])Grades move when new trials publish. A free monthly email lists every grade EBL moved, with the reason and the trial behind it: the sign-up is on the Evidence Log →