Another 1982 open trial study with 252 doctors and 1,506 patients conducted in Portugal provided good clinical information on appropriate dosage and usage of glucosamine sulfate for osteoarthritis. For 50 days, patients took 500 mg of glucosamine sulfate three times a day. The results showed 95% of the patients benefited from the supplement, as it reduced their pain whether they were resting, standing, or exercising. This study also showed the effects of glucosamine on obese patients; however, they may require higher dosages to offset the joints' reaction to the stress from obesity. Those patients also taking diuretics or suffering from peptic ulcers were also studied regarding the effect of, and their tolerance to, glucosamine. The former might require higher dosages and the latter need to take glucosamine with food.

In a more recent 2000 study at the ASA Harofeh Medical Center, in Ziffrin, 57 patients with osteoarthritis in the knee were treated randomly for four weeks with glucosamine sulfate intravenously combined with an 800 mg of chondroitin sulfate daily, or with a placebo. As in the 1982 study, a record was kept of their knee pain when at rest, standing, or moving. No reduction of symptoms occurred with the placebo group, but the glucosamine/chondroitin sulfate group showed much reduction of symptoms in all activity/non activity functions. This latter group also showed no negative reactions or any change in their blood tests. The study concluded that glucosamine sulfate is safe for long-term osteoarthritis treatment.

Another osteoarthritis study of the knee, in 1999 at the University of Liege in Belgium, involved 212 patients worldwide. These patients were randomly given either glucosamine or a placebo for three years. The patients' pain was measured every four months and x-rays were taken of their knees. The placebo group had more pain and narrowed joints, while the glucosamine group had no narrowing of joints and their condition improved. This was one of the first studies to show how glucosamine works by stopping the joints from narrowing. It was also the first long-term study conducted.

In 2003, researchers from the University of Western Australia reported that for a period of 12 weeks they gave glucosamine daily to a small group (24) of patients suffering from chronic knee pain. Most of the patients showed improved mobility between 4 to 8 weeks and 88% had reduced knee pain by the end of the 12 weeks.

More studies are continuing. The University of Utah School of Medicine was awarded a contract by the National Institutes of Health (NIH) to coordinate a study called NIH's Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT), which is being conducted at 13 research centers across the United States. The National Center for Complementary and Alternative Medicine (NCCAM) and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) are two components of the National Institutes of Health (NIH) that are responsible for initiating this study. The study started in April 2000 and is scheduled for completion November 2005. A preliminary report of results may be made as early as mid-2005.

A leading glucosamine formula is Syn-flex®. Syn-flex® is a fast-acting, high-quality osteoarthritis product for humans and pets. Formulated with pharmaceutical quality liquid glucosamine sulfate, glucosamine hydrochloride, chondroitin sulfate, and nine other arthritis-fighting ingredients, Syn-flex® will not only ease your pain quickly, it will slow the progression of your osteoarthritis. Learn more about Syn-flex® here.

J.R. Rogers is the founder and President of Activex America, Inc. makers of Liquid Glucosamine Formula Syn-flex®