Our knowledge of orthopaedics. Your best health.

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 and the U.S. for several decades, with few reported side effects.
• Both supplements also have some anti-inflammatory effects that may account for the pain relief.
• Several studies show modest short- and medium-term pain relief with either glucosamine or chondroitin sulfate, though most studies show no benefit to combining the two supplements.

There is no proof, however, that either substance, taken alone or in combination, will actually slow the degenerative process or restore cartilage in arthritic joints.

Although many people believe that traditional physicians will dismiss their interest in supplements, many doctors are actually quite open to complementary treatments. However, these supplements are not appropriate for all forms of arthritis or for all people. Diabetics and pregnant women, for example, should be especially cautious.

The effectiveness of these treatments is proven, and nutritional supplements should remain just that — complementary to your good health practices. You may need to take the supplements for a couple of months before you see any results, which makes it that much more important to continue your current treatments.

Find out about the supplement you are considering buying. Are there any side effects? Will it interact with your current medication? Write to the manufacturer and ask for documentation that supports their claims.

For additional information on glucosamine, visit the website for the National Institutes of Health (NIH).

Dietary supplements like glucosamine and chondroitin sulfate are not tested or analyzed by the Food and Drug Administration (FDA) 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."  The product may not actually contain the labeled ingredients or quantities of ingredients.

Because these products are not regulated, you must verify the ingredients on your own. Even products labeled "standardized" don't meet federal standards, just internal ones set by the manufacturer. Standards can vary among manufacturers, so avoid brand names you don't know.

If anything does go wrong and you experience some adverse side effects, report them to your doctor quickly and stop taking the product. Remember that any supplement potent enough to help is probably also strong enough to harm if taken inappropriately.

Sources: AAOS Research Committee fact sheet, Osteoarthritis, and the Arthritis Foundation

Singh JA, Noorbaloochi S, MacDonald R, Maxwell LJ. Chondroitin for osteoarthritis. Cochrane Database Syst Rev. 2015 Jan 28;1:CD005614. doi: 10.1002/14651858.CD005614.pub2. PMID: 25629804; PMCID: PMC4881293