Glucosamine sulfate, chondroitin and MSM, or methylsulfonylmethane, are supplements commonly used for relief from osteoarthritis, rheumatoid arthritis and joint inflammation. Glucosamine and chondroitin occur naturally in cartilage and other connective tissues. MSM is a natural form of sulfur found in plants, and it is also chemically made in the laboratory. Side effects vary with each of these supplements. Before taking any supplement, talk with your doctor.
Glucosamine
Glucosamine sulfate is used to treat osteoarthritis. Although it is well tolerated overall, glucosamine sulfate does have side effects and may cause allergic reactions. Reported side effects include insomnia, headaches, upset stomach, sensitivity to the sun and various skin reactions, according to the Mayo Clinic website. Glucosamine sulfate is often made from shellfish. If you have an allergy to shellfish, glucosamine sulfate may trigger an allergic reaction.
Glucosamine sulfate interacts with the blood thinner warfarin, increasing its effects, according to a study published in the April 2008 issue of “Pharmacotherapy.” The study examined a 71-year old man on warfarin who began taking 1,500 mg of glucosmine and 1,200 mg of chondroitin. Over a period of five weeks, his international normalized ratio, a test used to determine clotting, increased from 2.3 to 3.9 and ending at 4.7, when the supplement was stopped. The study concluded that using glucosamine with warfarin might result in increased bleeding.
Pregnant women should not take glucosamine without consulting with their doctors, due to limited studies on its effect in pregnant women.
Chondroitin
Chondroitin is often combined with glucosamine as a joint supplement. Chondroitin has few side effects but may cause nausea or diarrhea. Chondroitin has not been studied for use with children, according to the Mayo Clinic website. Both children and pregnant women should avoid it. Chondroitin is also contraindicated if you have a shellfish allergy. Besides shellfish, chondroitin may be made from bovine sources. There is a concern for the potential of getting bovine spongiform encephalopathy, or mad cow disease, cautions the Toxicology Data Network. Before purchasing a chondroitin product, determine its source.
MSM
MSM is sometimes combined with glucosamine supplements as an active ingredient but is also taken alone. Few conclusive studies on the use of MSM are available, but some side effects include stomach upset, headache and diarrhea, according to the Mayo Clinic website. Children should not take MSM, as there may be a relationship between MSM and autism. Further research is needed for evidence that is more conclusive.
Supplement Use Risks
Side effects from using a glucosamine, chondroitin or MSM supplement may also come from other ingredients in the product, such as fillers, binders and flavorings. Always read the label for added ingredients. Supplements are not created equal, and some contain higher-quality ingredients than others. Several independent organizations test and label products so the consumer is assured that the product contains only the listed items and is without harmful ingredients. Three such organizations are U.S. Pharmacopeia, ConsumerLab.com and NSF International, according to the Office of Dietary Supplements.
References
- eMedTV; Glucosamine and Chondroitin Dosage; K. Monson, PharD; October 2008
- MayoClinic.com; Glucosamine; August 2011
- Drugs.com; Chondroitin and Glucosamine; December 2010
- MayoClinic.com; Glucosamine Safety; August 2011
- "Pharmacotherapy"; Potential Glucosamine-Warfarin Interaction; J.F. Knudsen; April 2008
- MayoClinic.com; Chondroitin Sulfate Dosing; August 2011
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