Your body produces glucosamine and chondroitin naturally. Glucosamine plays a key role in building the tough connective tissue, or cartilage, that cushions your joints, while chondroitin is a major component of cartilage. Chondroitin also absorbs fluid -- including water -- into the cartilage to keep it healthy, while blocking enzymes that can break it down and providing the necessary building blocks to produce new cartilage. Studies researching the effectiveness of taking both glucosamine and chondroitin supplements to help osteoarthritis knee pain are mixed.
Osteoarthritis
Osteoarthritis, or OA, is a type of arthritis occurring when your cartilage breaks down and is lost, either due to injury or normal wear through aging. Symptoms of OA include pain and stiffness in the joints, especially following exercise or when you wake in the morning. No cure exists for OA, and it will probably become worse over time. However, you can control your symptoms by taking medications and making lifestyle changes. According to the University of Maryland Medical Center, several scientific studies show that glucosamine and chondroitin supplements may be an effective treatment for osteoarthritis. They may not only reduce pain but improve knee function while reducing joint swelling and stiffness. However, two large studies from 2006 and 2010 report mixed results on their effectiveness.
Effectiveness
A large 2006 study published in the "The New England Journal of Medicine" reported that glucosamine and chondroitin, whether given alone or in combination, do not reduce osteoarthritis knee pain overall. However, combining glucosamine and chondroitin does improve pain in a subgroup of patients who have moderate to severe knee pain. A 2010 paper in "BMJ" summarizing research on this topic concluded that glucosamine and chondroitin, either in combination or alone, do not reduce joint pain in people with osteoarthritis. Despite the fact that some studies do not report glucosamine and chondroitin to be effective, many do, so your doctor may recommend you try glucosamine for two to four months to see if it works for you.
Doses for Adults
MedlinePlus recommends taking 1500 mg of glucosamine daily, either at once or in 500-mg doses three times daily, and that you take 1000 to 1200 mg of chondroitin daily as a single dose or as 200- to 400-mg doses two to three times per day. These doses match what researchers gave participants in the 2006 study. You should not start these supplements without first talking to your doctor, who will be able to advise what dose is best for you according to your symptoms.
Considerations
Glucosamine may cause side effects, including upset stomach, drowsiness, insomnia, headache, skin reactions, sun sensitivity and nail toughening, reports MayoClinic.com. Glucosamine may also increase your risk of bleeding, so your doctor may alter your dose if you have a bleeding disorder or are on medications that increase your risk of bleeding. Chondroitin can also elicit side effects, such as mild stomach pain and nausea, along with diarrhea, constipation and irregular heartbeat.
References
- University of Maryland Medical Center; Glucosamine; Steven D. Ehrlich, NMD; June 21, 2009
- University of Maryland Medical Center; Chondroitin; Steven D. Ehrlich, NMD; June 21, 2009
- "The New England Journal of Medicine"; Glucosamine, Chondroitin Sulfate, and the Two in Combination for Painful Knee Osteoarthritis; Daniel O. Clegg, et al.; Feb. 23, 2006
- "BMJ"; Effects of Glucosamine, Chondroitin, or Placebo in Patients with Osteoarthritis of Hip or Knee: Network Meta-Analysis; Simon Wandel, et al.; July 5, 2010
- MedlinePlus; Glucosamine Sulfate; Nov. 18, 2010
- MedlinePlus; Chondroitin Sulfate; Nov. 18, 2010
