In degenerative joint disease, such as osteoarthritis, there is a loss of chondroitin sulfate as the cartilage erodes. Animal studies indicate that chondroitin sulfate may promote healing of bone, which is consistent with the fact that the majority of glycosaminoglycans found in bone consist of chondroitin sulfate. Chondroitin sulfate has been shown, in numerous double-blind trials, to relieve symptoms and possibly slow the progression of, or reverse, osteoarthritis.

Chondroitin and similar compounds are present in the lining of blood vessels and the urinary bladder. They help prevent abnormal movement of blood, urine, or components across the barrier of the vessel or bladder wall. Part of chondroitin’s role in blood vessels is to prevent excessive blood clotting. However, whether supplements of chondroitin are able to favorably affect blood clotting remains unclear. In addition, chondroitin sulfate may lower blood cholesterol levels. Older preliminary research showed that chondroitin sulfate may prevent atherosclerosis in animals and humans and may also prevent heart attacks in people who already have atherosclerosis.

Chondroitin sulfate can help form a coating on nasal passages. Perhaps as a result, researchers found that when chondroitin sulfate was sprayed into the nasal passages of a small group of people who snore, the amount of time people spent snoring was reduced about one-third in a double-blind trial. No further studies have investigated the effects of oral chondroitin sulfate on snoring.

Chondroitin sulfate is rich in sulfur and is related to glucosamine. GAGs affect how the body processes oxalate a substance linked to kidney stones. In one study of 40 people with a history of kidney stones, 30 mg twice a day of mixed GAGs reduced urinary oxalate excretion in 15 days a change that could drop the risk of stone formation. However, studies on the effect of GAGs on stone formation in humans have produced inconsistent results.

Glucosamine and Chondroitin Sulfate

About 30 million Americans suffer from osteoarthritis, an often painful condition in which the cushioning cartilage between bones wears away. Many people are trying new therapies and dietary supplements such as glucosamine and chondroitin sulfate in their search for relief.

Glucosamine is found naturally in the body. It stimulates the formation and repair of articular cartilage. Over-the-counter supplements come from animal sources. Chondroitin sulfate is another natural substance found in the body. It prevents other body enzymes from degrading the building blocks of joint cartilage. The type sold in health-food stores and pharmacies is derived from animal products.

The hope and the hype

People who use these nutritional supplements hope that they will relieve the pain of osteoarthritis, and perhaps even repair or restore the joint cartilage. Recent evidence seems to support the first claim. Both glucosamine and chondroitin sulfate have been used in Europe for several years, with few reported side effects. Both supplements also have some anti-inflammatory effects that may account for the pain relief.

But there is no proof that either substance, taken singly or in combination, will actually slow the degenerative process or restore cartilage in arthritic joints. All studies done to date have been short and focused on pain relief. A long-term study is just beginning, sponsored by the National Institute of Arthritis and Musculoskeletal and Skin Diseases and the National Center for Complementary and Alternative Medicine.

Dietary supplements like glucosamine and chondroitin sulfate are not tested or analyzed by the Food and Drug Administration before they are sold to consumers. That means consumers can’t be sure they’re getting what they pay for when they purchase bottles labeled "Glucosamine/Chondroitin." In fact, a recent study by ConsumerLab.com showed that almost half of the glucosamine/ chondroitin supplements tested did not contain the labeled amounts of ingredients.

Symptoms of Deficiency or Need:

For patients who have evidence of osteoarthritis in their spine (as seen on an x-ray) and who have had other causes of back pain and neck pain ruled out by their health care provider, glucosamine sulfate and chondroitin sulfate may be a treatment option.

For atherosclerosis, researchers have sometimes started therapy using very high amounts, such as 5 grams twice per day with meals, lowering the amount to 500 mg three times per day after a few months. Before taking such high amounts, people should consult a doctor. For osteoarthritis, a typical level is 400 mg three times per day. Oral chondroitin sulfate is rapidly absorbed in humans when it is dissolved in water prior to ingestion. Approximately 12% of chondroitin sulfate taken by mouth becomes available to the joint tissues from the blood.

Nausea may occur at intakes greater than 10 grams per day. No other adverse effects have been reported.

One doctor has raised a concern that chondroitin sulfate should not be used by men with prostate cancer. This concern is based upon two studies. In one, the concentration of chondroitin sulfate was found to be higher in cancerous prostate tissue as compared to normal prostate tissue. In the other study, it was shown that higher concentrations of chondroitin sulfate in the tissue surrounding a cancerous prostate tumor predict a higher rate of recurrence of the cancer after surgery. However, no studies to date have addressed the question of whether taking chondroitin sulfate supplements could promote the development of prostate cancer. Simply because a substance is present in or around cancerous tissue does not by itself suggest that that substance is causing the cancer. For example, calcium is a component of atherosclerotic plaques that harden the arteries; however, there is no evidence that taking calcium supplements causes atherosclerosis. To provide meaningful information, further studies would need to track the incidence of prostate cancer in men taking chondroitin supplements. Until then, most nutritionally-oriented doctors remain unconcerned about this issue.

It is not known whether taking glucosamine sulfate and chondroitin sulfate in combination is a more effective treatment for osteoarthritis than taking either one by itself.

At the time of writing, there were no well-known drug interactions with chondroitin sulfate.

Natural Sources?
The only significant food source of chondroitin sulfate is animal cartilage.