Chondroitin sulfate

About Chondroitin sulfate

A long sulfated glycosaminoglycan chain that forms part of cartilage matrix, extracted from bovine trachea, porcine and avian cartilage, or shark cartilage. It is usually sold alongside glucosamine.

Chondroitin has the same contested status as glucosamine and an additional problem of its own: product quality. Independent analyses have repeatedly found retail chondroitin products containing far less than the labelled amount, sometimes a small fraction of it, because the raw material is expensive and adulteration with cheaper polysaccharides is straightforward. Trial results split much as they do for glucosamine — pharmaceutical-grade preparations in European trials report modest pain reduction and slowed joint space narrowing, while independent trials and the GAIT study report little. Cochrane concluded the quality of evidence is low and the effects small, and the American College of Rheumatology recommends against it while ESCEO recommends the pharmaceutical-grade product. The honest summary is contested, not established.

Sold as

Tablet, Capsule, Combination with glucosamine and MSM, Pharmaceutical-grade preparation (Europe)

Standardised to

Milligrams of chondroitin sulfate; molecular weight and purity differ substantially by species of origin and by manufacturer — a product without this marker may not resemble what was studied.

Also known as

Chondroitin, Chondroitin sulphate A, CS

Regulation: A dietary supplement in the US with no pre-market efficacy review; a prescription or pharmacy medicine for osteoarthritis in parts of Europe. Guideline bodies disagree, as they do for glucosamine.

What the research used

The amounts, forms and durations published trials of Chondroitin sulfate actually administered.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.