A study published in the British Journal of Sports Medicine examined the effects of glucosamine supplementation on functional ability and chronic knee pain in individuals with previous cartilage damage or osteoarthritis.

Subjects were randomly supplemented with either glucosamine or placebo for 12 weeks at a dose of 2,000 mg per day. Four testing sessions were conducted during the study. Changes in knee pain and function were determined by clinical and functional tests (joint line palpation, a 3 meter “duck walk,” and a repeated walking stair climb). Additionally, two different questionnaires were used to evaluate changes in pain.

The glucosamine group was found to have significantly better quality of life scores at weeks 8 and 12 than the placebo group. Based on self-report evaluations of changes during the 12 week supplementation period, 88% of the glucosamine group reported some degree of improvement in their knee pain versus only 17% in the placebo group.

These results suggest that glucosamine supplementation can provide some degree of pain relief and improved function in individuals who experience chronic knee pain due to previous cartilage damage or osteoarthritis. The results also suggest that at a dosage of 2,000 mg per day, the majority of improvements are apparent after eight weeks.

Br J Sports Med 2003 Feb;37(1):45-9