Like HowStuffWorks on Facebook!

Glucosamine and Chondroitin

Q:  I am 51 years old and I have had arthritis in my hip joints for many years. I have tried taking arthritis medications but they upset my stomach too much. My doctor tells me I may need a hip replacement but suggested I try a supplement called "glucosamine and chondroitin" to help my hip. What are glucosamine and chondroitin and will these medications be an effective treatment for my arthritis?

A:  Glucosamine and chondroitin sulfate are actually considered to be food supplements that have been used for many years by veterinarians to treat dogs suffering from arthritic joints. These food supplements, also called "nutriceuticals," are derived from animal products. They are used in combination with one another and are very popular among veterinarians, because they appear to help decrease the pain, inflammation and other symptoms of arthritis in their canine patients. Because of its known value in veterinary medicine, these nutriceuticals have received a lot of attention from medical researchers in hopes that they will also provide a new avenue of needed pain relief to human patients with osteoarthritis (OA).

Glucosamine and chondroitin have even been used in Europe over the past 10 years as a supplement for humans with OA, and have just recently been given serious evaluation by the medical community in the United States. The preparation is taken by mouth and is absorbed into the body's system by the gastrointestinal tract. Because the United States Food and Drug Administration (FDA) considers them to be "food supplements," however, glucosamine and chondroitin have not undergone rigorous research testing that is required for bona fide drugs.

OA is caused by the inflammation, erosion and degradation of tissues in skeletal joints, such as joints located in the hip, shoulder, elbow, knees, hands or ankles. Each joint is layered with cartilage called "articular cartilage" and it plays a very important role in the structure and function of a healthy joint. When this specialized protective layer of cartilage gets worn down by a disease process or wear and tear, erosion to the bone joint can subsequently occur. This breakdown can then cause the joint to be painful, stiff, tender, swollen and inflamed. Erosion can get so bad that the joint no longer has any cushion or lubrication to help it rotate in different directions. As a result, joints with OA can feel like there is sand paper in the joint, causing the slightest movement of the joint to painfully grind rough edges against the adjacent bones.

Articular cartilage is comprised of special molecules called "proteoglycans" and glucosamine and chondroitin are considered one of the basic chemical building blocks that make up proteoglycans. Although it is uncertain how these nutriceuticals actually work in the diseased joint, medical researchers theorize that they may replace these needed proteoglycan building blocks, thereby possibly contributing to the important repair of lost healthy articular cartilage.

Glucosamine and chondroitin are available over-the-counter in stores, and therefore don't require a prescription from your doctor. It is usually prepared as one tablet, with 1,500 mg of glucosamine and 1,200 mg of chondroitin. For the most part, these preparations appear relatively safe, although more scientific testing is required before we will know all of the short- and long-term effects of these neutriceuticals on the body's joints and other systems. There is presently some concern that glucosamine may be related to an increase risk of the onset of adult diabetes. Because the FDA has no control over the quality of each manufacturer's supply, the purity of the substances also cannot be guaranteed.

The clinical studies completed to date in the United States conclude that these preparations may provide a moderate, beneficial effect for the symptoms of OA. Some studies have even shown that 50 - 80% of patients who took these nutriceuticals for the symptoms of OA had improvement of their symptoms, when compared to patients who received placebos (pills with no active ingredients).

Important studies of glucosamine and chondroitin are now being conducted in the United States to determine their safety and efficacy, in addition to the potential side effects when they are taken for long periods of time. Because the jury is still out regarding these clinical trials, be sure to inform your doctor if you are taking these nutriceuticals.

Scott Fishman, M.D., is a leading expert in pain management.