The following is an excerpt from Arthritis Alerter, published by the Arthritis Foundation (Summer 1999)

“Just the facts…Glucosamine and Chondroitin Sulfate”

“This information does not cover all possible uses, actions, precautions, side effects or interactions of glucosamine and chondroitin sulfate. It should not replace the advice and guidance given by your doctor. Glucosamine and chondroitin sulfate are nutritional supplements and as such as not subject to the same rigorous regulation as prescription and nonprescription drugs. If you have questions about these or other dietary supplements, ask your doctor or pharmacist. The Arthritis Foundation does not endorse any brand name or generic supplement listed.”

What are glucosamine and chondroitin sulfate? “Glucosamine and chondroitin sulfate are found naturally in the body. Glucosamine is a form of amino sugar believed to play a role in cartilage formation and repair. Chondroitin sulfate is part of a large protein molecule (proteoglycan) that gives cartilage elasticity. Both glucosamine and chondroitin are substances found naturally in the body. They are extracted from animal tissue: glucosamine from crab, lobster or shrimp shells; and chondroitin from animal cartilage. Chondroitin sulfate is extracted from the cartilage of cattle tracheas, but can be extracted from shark cartilage.”

What are they used for? “These supplements have been used to treat osteoarthritis in horses and dogs for several years. In Europe, people have used glucosamine and chondroitin sulfate to treat osteoarthritis since the 1980s. These supplements have not yet been studied in the treatment of other forms of arthritis or related conditions, such as rheumatoid arthritis or gout, or in other causes of pain such as stress fractures.

What do they do? “In past studies done primarily in Europe, some people with mild to moderate osteoarthritis who took either glucosamine or chondroitin sulfate reported pain relief at a level similar to that of nonsteroidal anti-inflammatory drugs (NSAIDS) such as aspirin and ibuprofen. Although some researchers speculate that the supplements may slow cartilage loss in people with osteoarthritis, there is no evidence that this occurs. Long-term, double-blind, controlled scientific studies to assess the benefits and safety of the supplements are currently being conducted, including an in-depth clinical study by the National Institutes of Health.”
What Do I Look For? “Glucosamine comes in several forms called salts, usually either glucosamine sulfate or glucosamine hydrochloride. Both forms have been reported to work equally well although most studies have been done with the sulfate form. Experts recommend taking chondroitin sulfate in supplement form. Some shark cartilage products contain chondroitin sulfate, but the quality and amount in these produces are inconsistent. Because dietary supplements are unregulated, the quality and content may vary widely. If you decide to take these supplements, choose products made by well-established companies that can be held accountable. Read the product labels carefully to make sure the ingredient lists make sense to you. If you have trouble, ask your pharmacist for help. Recommended doses should costs about $1 to $3 per day. This cost is not covered by most insurance companies. Be sure to consult your doctor before trying these supplements. Make sure osteoarthritis is the cause of your pain. Do not stop or reduce your current prescribed medications without talking with your doctor.”

How Do I Take Them? “Whereas some experts recommend taking glucosamine alone, others recommend only chondroitin sulfate, and some recommend both. Taking glucosamine and chondroitin together has not been shown to increase their individual effects. If you decide to take either or both of these supplements, experts recommend taking the amount that has been used in the studies. For glucosamine this amount is 1,500 milligrams (mg) per day; for chondroitin it is 1,200 mg per day. You can try the supplements along with your current medications for 6 to 8 weeks. If you don’t experience any difference in your symptoms within a few months, you probably will not get any relief from using the supplements. Some people may get partial relief by using the supplements, but they may still have to take medications for full relief. If you have advanced osteoarthritis with a great deal of cartilage loss, glucosamine and chondroitin probably will not help you.”

Are there side effects? “Common side effects of glucosamine and chondroitin sulfate are increased intestinal gas and softened stools. If you experience these problems, you may want to try another supplement brand before you stop using the supplements altogether. (See Cautions, below for more details). More studies need to be done to confirm the safety and effectiveness of the supplements. Be sure to consult your doctor if you notice any unusual or new symptoms while you are taking glucosamine and/or chondroitin sulfate. Keep in mind that, unlike drugs, these supplements are not regulated by the FDA. The quality and effectiveness of the products available in stores may vary widely.”

Cautions “Although not enough studies have been done on glucosamine and chondroitin sulfate to know all of the necessary precautions, some people should be especially careful when considering these supplements.

  • Children, women who are pregnant, and women who could become pregnant should not take these supplements. These substances have not been studied long enough to determine their effects on a child or on a developing fetus.
  • Because glucosamine is an amino sugar, people who have diabetes should check their blood sugar levels more frequently if they take this supplement.
  • If you are taking chondroitin sulfate in addition to a blood-thinning medication or daily aspirin therapy, have your blood clotting time checked more often. This supplement is similar in structure to the blood-thinning drug heparin, and the combination may cause bleeding in some people.
  • If you are allergic to shellfish, consult your doctor before deciding to take glucosamine. In most cases; however, allergies are caused by the protein in shellfish, not by chitin, a carbohydrate from which glucosamine is extracted.”