Glucosamine is a chemical compound produced in the body that helps build cartilage, the connective tissue that cushions the joints. Different types of glucosamine supplements are available, such as glucosamine sulfate and glucosamine hydrochloride. Most are derived from the shells of crustaceans, although some manufacturers produce a synthetic version for people who do not eat shellfish. Glucosamine shows benefits for treating joint pain, including knee pain. Consult with a qualified health-care provider before taking glucosamine supplements.
Osteoarthritis
Glucosamine sulfate is a common supplemental remedy for symptoms of mild and moderate osteoarthritis. Scientists have conducted a large amount of research on glucosamine for this use, particularly for knee arthritis, according to the U.S. National Institutes of Health at its MedinePlus website. Some research indicates that glucosamine relieves osteoarthritis knee pain about as well as the over-the-counter medicines acetaminophen and ibuprofen, although it takes longer to begin working. Glucosamine sulfate also may slow the progression of osteoarthritis when people take it on a long-term basis. While some research has not found significant benefits, the studies either did not use glucosamine in the form of glucosamine sulfate, or people in the studies had more severe pain than glucosamine appears to help.
Specifics
A study published in the February 2003 issue of the "British Journal of Sports Medicine" evaluated the effects of glucosamine supplements on individuals with knee pain most likely caused by prior cartilage damage and possibly osteoarthritis. A total of 88 percent of the group taking glucosamine reported improvement in their knee pain, while 17 percent of the placebo group did so. The glucosamine group also showed significantly better indications of quality of life.
Limitations
Researchers found some significant benefits of glucosamine supplementation for athletes with acute knee injury during a study that appeared in the April-June issue of "Research in Sports Medicine." After 28 days of treatment, these athletes had better joint flexibility than participants in a placebo group. However, glucosamine did not improve pain symptoms during resting or walking, or knee swelling.
How It Works
Glucosamine supplements may either increase the cartilage and synovial fluid surrounding the joints or prevent deterioration of these substances, or do both, according to the U.S. National Institutes of Health at its MedlinePlus website. Glucosamine sulfate appears more useful for relieving knee pain than other types of glucosamine, perhaps because the body needs sulfate to build cartilage.
Considerations
Not everyone experiences pain relief when using glucosamine supplements, notes MedlinePlus. Glucosamine may not be as effective for people with severe or long-term osteoarthritis, or for overweight or elderly individuals. Glucosamine can take up to eight weeks to begin working.
