Glucosamine is a compound found naturally in the body, made from glucose and the amino acid glutamine. Glucosamine is needed to produce glycosaminoglycan, a molecule used in the formation and repair of cartilage and other body tissues.
Since production of glucosamine slows with age, some people use glucosamine supplements to fight aging-related health conditions, such as osteoarthritis. Taking glucosamine as a nutritional supplement is thought to keep osteoarthritis in check by restoring the body's glucosamine supply and repairing damaged cartilage.
Glucosamine With Chondroitin or MSM
Glucosamine is often combined with chondroitin sulfate, a molecule naturally present in cartilage. Chondroitin gives cartilage elasticity and is believed to prevent the destruction of cartilage by enzymes. In some cases, glucosamine is also combined with methylsulfonylmethane (or MSM) in nutritional supplements.
Uses for Glucosamine
Proponents claim that glucosamine can help treat these health problems:
- high cholesterol
- inflammatory bowel disease (such as ulcerative colitis)
- rheumatoid arthritis
- temporomandibular joint disorder (also known as "TMD" or "TMJ")
The Science Behind Glucosamine
Research suggests that glucosamine may help with certain health conditions. Here's a look at the study findings:
Glucosamine is likely effective for the treatment of osteoarthritis (especially osteoarthritis of the knee), according to the National Institutes of Health (NIH). Indeed, a 2005 report published in the Cochrane Database of Systematic Reviews concluded that some preparations of glucosamine may reduce pain and improve functioning in people with osteoarthritis. For the report, researchers analyzed 20 studies (with a total of 2,570 patients) on the use of glucosamine in treatment of osteoarthritis.
There's also some evidence that glucosamine can slow the progression of osteoarthritis. In a 2002 study from Archives of Internal Medicine, for example, 202 people with mild to moderate osteoarthritis took either 1,500 mg of glucosamine or a placebo daily for three years. At the end of the study, researchers found that glucosamine slowed the progression of knee osteoarthritis and reduced pain and stiffness. What's more, x-rays revealed no overall change or narrowing of joint spaces in the knees (a sign of deterioration) among members of glucosamine group. In contrast, joint spaces in placebo-taking participants had narrowed over the three years.
One of the largest studies on glucosamine for osteoarthritis was a 6-month study sponsored by the National Institutes of Health and published in the New England Journal of Medicine in 2006. Called GAIT, the study compared the effectiveness of glucosamine, chondroitin sulfate, a combination of glucosamine and chondroitin sulfate, the drug celecoxib (Celebrex), or a placebo in people with knee osteoarthritis.
Glucosamine or chondroitin alone or in combination didn't reduce pain in the overall group, although people in the study with moderate-to-severe knee pain were more likely to respond to glucosamine.
One major drawback of the GAIT Trial was that glucosamine hydrochloride was used rather than glucosamine sulfate (a more widely used and researched form of glucosamine). For a 2007 report published in Arthritis and Rheumatism, investigators analyzed previous research on glucosamine (including the GAIT Trial) and concluded that glucosamine hydrochloride was not effective. The analysis also found that studies on glucosamine sulfate were too different from one another and were not as well-designed as they should be, so they could not properly draw a conclusion. More research is needed.
2) Temporomandibular Joint Osteoarthritis
Glucosamine is possibly effective for temporomandibular joint osteoarthritis, according to the NIH. In a 2001 study from the Journal of Rheumatology, researchers found that glucosamine alleviated pain among a group of adults with this condition. For the study, 45 patients took either glucosamine or ibuprofen for 90 days. Of the 39 people who completed the study, 15 of 21 (71%) members of the glucosamine group and 11 of 18 (61%) members of the ibuprofen group achieved a positive clinical response (20% or more improvement in TMJ pain with use).
3) Low Back Pain
Glucosamine may not benefit people with chronic low back pain and degenerative lumbar osteoarthritis, according to a 2010 study from the Journal of the American Medical Association. For six months, 250 patients with both conditions took either glucosamine supplements or a placebo. Study results revealed that glucosamine did not reduce low back pain or pain-related disability.
Very limited evidence indicates glucosamine could be a treatment for glaucoma, according to a 2001 report from Alternative Medicine Review. However, due to the lack of clinical trials testing glucosamine's effectiveness as a glaucoma treatment, it's too soon to recommend glucosamine as a glaucoma therapy.
Where to Find Glucosamine Supplements
Glucosamine is available as a nutritional supplement in health food stores and many drug stores. Glucosamine is also used in some sports drinks and in cosmetics.
Glucosamine supplements are manufactured in a laboratory from chitin, a substance found in the shells of shrimp, crab, lobster, and other sea creatures.
Side Effects and Safety of Glucosamine
Most studies involving humans have found that short-term use of glucosamine is well-tolerated. Read about the side effects of glucosamine.
Should You Use Glucosamine for Health Purposes?
Glucosamine may be of some benefit to people with osteoarthritis. It's important to note that health care providers often suggest a three-month trial of glucosamine and discontinuing it if there is no improvement after three months.
If you're considering the use of glucosamine in treatment of any chronic condition, talk to your doctor before starting your supplement regimen.