Glucosamine

Glucosamine is extracted from a material (chitin) present in the shells of crabs, oysters, and shrimp. Glucosamine can be applied topically in a cream or salve or taken in tablet or capsule form, usually as glucosamine sulfate, but sometimes as glucosamine hydrochloride. Glucosamine often is taken with chondroitin sulfate Chondroitin Sulfate Chondroitin sulfate is a natural component of cartilage. It is extracted from shark or cow cartilage or manufactured synthetically. It is frequently combined with glucosamine. Chondroitin sulfate... read more .

(See also Overview of Dietary Supplements Overview of Dietary Supplements Dietary supplements are used by about 75% of Americans. They are the most common therapies included among integrative medicine and health (IMH) and complementary and alternative medicine (CAM)... read more .)

People take glucosamine mostly to treat osteoarthritis Osteoarthritis (OA) Osteoarthritis is a chronic disorder that causes damage to the cartilage and surrounding tissues and is characterized by pain, stiffness, and loss of function. Arthritis due to damage of joint... read more of the knee. Its role in treating osteoarthritis in other locations is less well-defined.

Evidence is conflicting. Some evidence suggests it has both pain-relieving and disease-modifying effects, whereas other large and well-designed studies show it to be of no benefit. One large study has shown that glucosamine hydrochloride is beneficial when combined with chondroitin sulfate. Evidence supports use of glucosamine sulfate from a specific manufacturer, Rotta Research Laboratorium, for mild to moderate osteoarthritis in the knee when taken for at least 6 months. The benefit of glucosamine for severe osteoarthritis in the knee or osteoarthritis in other locations is less clear.

Glucosamine is safe for most people. Common side effects are itching and mild digestive problems such as heartburn, diarrhea, vomiting, and nausea. Other side effects include fatigue, headache, difficulty sleeping, sun sensitivity, and nail changes. People with liver disease should avoid glucosamine if possible. People who have a shellfish allergy and take glucosamine extracted from shellfish may have an allergic reaction. Some people with asthma have had flares.

High-dose glucosamine may interact with warfarin and result in bruising or bleeding, according to case reports and information submitted to the World Health Organization. No other important drug interactions are known.

Glucosamine is generally considered safe, but evidence of its benefits is limited. People with osteoarthritis Osteoarthritis (OA) Osteoarthritis is a chronic disorder that causes damage to the cartilage and surrounding tissues and is characterized by pain, stiffness, and loss of function. Arthritis due to damage of joint... read more of the knee may consider talking to their doctor about adding glucosamine (usually combined with chondroitin sulfate) to their treatment plan. However, its use is not endorsed by organizations of specialists that treat osteoarthritis.

People who take warfarin should talk to their doctor about monitoring for their risk of bleeding.