Evidence continues to mount that glucosamine, while generally safe, is not effective in treating osteoarthritis of the knee. In the latest study, Dr. Tim McAlindon and colleagues from Tufts-New England Medical Center in Boston randomly assigned 205 adults with painful knee osteoarthritis to take glucosamine (1.5 grams per day) or a placebo for 12 weeks. Ninety-three participants in each group completed the trial. At the end of the study there were no significant differences between glucosamine and placebo in terms of changes in pain scores. There were also no marked differences between glucosamine and placebo in terms of stiffness, physical function, and use of painkillers, the team reports in the American Journal of Medicine.