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April 2, 2001
Nature's Cure for Osteoarthritis?
Glucosamine and chondroitin supplements shown to provide relief
By Christopher Chaput, M.D.

Illustration: Glucosamine

How long could you drive your car down the highway with four blown tires, scraping along on just the rims? Imagine that grinding of metal happening inside your body -- this is how a person suffering from osteoarthritis might feel with each step. Osteoarthritis is the end result of too much wear and tear on the joints' natural buffer of cartilage, which can degrade until bone is rubbing on bone. Grinding pain in the elbows or knees can make it difficult for a patient to simply get dressed in the morning or stand up from the kitchen table. The best we can do with traditional therapies for osteoarthritis is to treat the painful symptoms; no conventional medication has been proven to slow the progression of the disease. Moreover, the medications and injections used to treat osteoarthritis often provide only minimal relief and can have significant, occasionally life-threatening side effects.

It never surprises me, then, to find some of my patients eager to go beyond the boundaries of conventional treatments in hopes of relief. One man was so desperate that he walked around with a large magnet taped to his knee. He claimed it helped some, and who was I to tell him otherwise? With no effective treatment for their pain, many arthritis patients turn to alternative medicine, trying everything from copper bracelets to dietary supplements in order to relieve their suffering. Unfortunately, most home remedies and alternative treatments for osteoarthritis work about as effectively as burning chicken feathers, and their use is usually unsupported by serious research. But when some of my patients told me they were experiencing less pain thanks to "miracle" supplements called glucosamine and chondroitin sulfate, I was skeptical but interested.

As a doctor, I just want to be able to tell my patients with reasonable confidence that a therapy has some chance of benefiting them and little chance of harming them. Nobody likes to be helpless, and that is exactly how many patients feel as they gradually stop doing the activities they enjoy in life because of the pain gnawing at their joints. I try to put myself in their position -- if I had osteoarthritis, I would try anything that didn't hurt me if I thought it might help. I decided to investigate glucosamine and chondroitin with a critical eye in an effort to give my patients every option that might help them. And I was surprised to find out that there is good evidence that these two dietary supplements may actually help people suffering from osteoarthritis, without many adverse effects.

What are glucosamine and chondroitin?

Both glucosamine sulfate and chondroitin sulfate are found naturally in all connective tissues in the body, including cartilage. Early studies have shown that these supplements can reduce the pain of osteoarthritis, at least for the short-term. Several studies have also suggested that these substances may actually help protect cartilage from the degeneration that leads to arthritis. It should be noted, however, that there has not yet been a conclusive study demonstrating that these supplements can prevent, halt, or reverse osteoarthritis.

Glucosamine and chondroitin act in very similar ways but should be examined separately for the benefits they may provide a patient with osteoarthritis.


Glucosamine sulfate serves as the primary building block for proteoglycans -- large molecules in cartilage that give it viscoelastic, or buffering, properties. When glucosamine sulfate is taken as a supplement, it is absorbed readily into the system and can be traced to cartilage as soon as four hours after consumption. Glucosamine sulfate also has unique anti-inflammatory effects, and in some laboratory tests has been shown to have a protective effect on the cartilage itself, perhaps by driving the process of cartilage synthesis forward and inhibiting the breakdown of cartilage.

Glucosamine hydrochloride is another form of glucosamine, and though fewer studies have been done using the hydrochloride form, it is probably as effective as the sulfate form. This form can be absorbed more readily, so less has to be taken to get an equivalent amount in your system.

Chondroitin sulfate

Chondroitin sulfate is a much larger molecule that can also be found in cartilage. It's been studied much less extensively, but early results show that it also seems to work as an anti-inflammatory and pain reducer. Some studies suggest it can also slow cartilage breakdown and may even spur cartilage growth.

Who should take these dietary supplements?

This is a judgment that should be made by patients and their health care provider. When I discuss these issues with my patients, I follow certain criteria:

  • Does the patient have osteoarthritis? Normally I recommend glucosamine and chondroitin only for patients who have osteoarthritis. I make this diagnosis by talking to the patient, examining the patient, and then taking X rays for confirmation.
  • Is the patient interested in alternative treatments for pain and willing to follow what could be a long-term regimen of therapy?
  • Is the patient interested in trying to preserve his or her cartilage for as long as possible, interested in alternative medications, and willing and able to purchase and take this medication for the long term, even though the protective effects on cartilage are not certain?

Occasionally, a patient will come in with a nonspecific joint pain and I will not have a definite diagnosis despite a thorough workup. If the patient expresses interest in alternative therapies, I may recommend trying these substances for their probable anti-inflammatory effects.

How do I take chondroitin and glucosamine?


Both supplements are taken orally in tablet or capsule form. Be aware that currently there are few standardized and adequately tested dietary supplements. Ask your health care provider and your pharmacist for suggestions on which brand they believe has the highest-quality product. Also, seek out the manufacturer on the Internet or from information on the bottle and ask about the methods of quality assurance used for the product.


Participants in studies are usually given a daily therapeutic dose of 1,500 milligrams for glucosamine sulfate and 1,200 milligrams for chondroitin sulfate.

Length of treatment

These substances do not work overnight. Reported improvement varies from three to eight weeks. Generally, if there is no pain reduction after two months, discontinue use. Keep a diary of your symptoms when you begin treatment to better judge changes in your pain level or joint movement, and share this information with your doctor.

Will these supplements prevent osteoarthritis?

The studies have concentrated on pain reduction and on the possibility of cartilage regrowth. I leave it up to the patient to decide whether or not to take these supplements solely for the prevention of cartilage loss. There are no conclusive studies on glucosamine and chondroitin as preventive medicines against osteoarthritis.

Can these supplements hurt me?

The preliminary studies show glucosamine and chondroitin to be remarkably safe and well tolerated. Be aware, however, that even substances naturally found in the body can have unpredictable results when taken in higher than normal quantities or in different formulations. This is especially true for people on multiple medications.

Nausea, diarrhea, and gastrointestinal upset are the most common adverse effects, and they are reported in only a small percentage of patients. In addition, some laboratory studies suggest that glucosamine may increase insulin resistance. Therefore, diabetic patients should use these substances with caution and only under medical supervision.

What's the bottom line, Doctor?

Not long ago I heard this question asked of one of my clinical professors. His response summed up my feelings: "This stuff is cheap, it probably won't hurt you, and it might do you some good." If I had osteoarthritis, I might give glucosamine and chondroitin a try. Of course, I wouldn't expect a miraculous cure. As with most human diseases, there are few magic bullets.

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