If your aching knees, shoulder or hands have you reaching for the aspirin bottle on a daily basis, you're in good company. Osteoarthritis, an age-related disorder caused by cartilage degeneration in joints, affects nearly everyone to some degree by age 70, according to the National Institutes of Health. Glucosamine sulfate may reduce the cartilage damage that leads to pain and disability as well as reducing your dependence on nonsteroidal anti-inflammatory medications, which can have significant side effects. Glucosamine, which comes in 500, 750 and 1,000 mg doses, can also have side effects.
Because glucosamine is made from shellfish, people who have shellfish or iodine allergies should exercise caution when taking glucosamine, MayoClinic.com warns. Allergic reactions normally occur to proteins, and glucosamine is made from chitin, the carbohydrate in shellfish. Although there may not be enough shellfish protein in the product to trigger an allergic reaction, allergic reactions including throat swelling have occurred. Talk to your doctor before taking glucosamine if you have allergies to shellfish.
Blood Glucose Effects
The effects of glucosamine on blood glucose levels are not clear, according to MayoClinic.com. Animal research indicates that the drug may increase insulin resistance, a contributor to development of Type 2 diabetes, says Stephen Barrett, M.D., of Quackwatch.com. Although studies do not show an effect on hemoglobin A1c levels, which are used to monitor average blood sugar levels in diabetics over a three-month period, diabetics should monitor blood sugar levels carefully when taking glucosamine.
Glucosamine can cause a number of stomach-related side effects, including gas, upset stomach, abdominal pain, nausea, vomiting, loss of appetite, loose stools, heartburn and constipation. Gastrointestinal side effects normally occur at doses several times the normal dose, according to the Arthritis and Glucosamine Information Center.
Other Side Effects
Other potential side effects of glucosamine include sleep disturbances such as insomnia or drowsiness; headache; and skin reactions, including increased sun sensitivity and nail hardening. Increased heart rate, irregular heartbeat or elevated blood pressure has occurred in some people.
Potentially Serious Complications
Glucosamine could theoretically increase the risk of bleeding in people who take blood thinners, according to MayoClinic.com. Impurities in some glucosamine products may cause increased levels of creatine phosphokinase in the blood, which could alter laboratory blood tests results. Kidney damage has also been reported in people taking the drug. Several deaths from liver failure were reported in people taking glucosoamine in Scotland. While cause and effect was not established, warnings were issued by local physicians, Barrett reports.