Ask the Doctors

Dear Doctor: A friend suggested I try MSM crystals for arthritis. What are they, and do they work? If they do, where can I find them?

Dear Reader: Methylsulfonylmethane (MSM) is an organic sulfur-containing compound naturally found in plants such as Brussels sprouts, garlic, asparagus, kale, beans and wheat germ. It can also be found in horsetail, an herbal remedy. MSM, which has been touted as a treatment for arthritis, is related to a similar compound, dimethyl sulfoxide (DMSO), that has been shown to have anti-inflammatory properties. MSM may have anti-inflammatory properties as well, but different from those associated with aspirin or nonsteroidal anti-inflammatory agents (NSAIDs). Unlike DMSO, which is a liquid applied at room temperature, MSM is a white crystalline compound -- hence the reference to "crystals."

As for whether it works, let's look at the evidence. A 2011 study performed in Israel assessed its impact on 50 people with arthritis of the knee. Twenty-five patients took a placebo, while 25 took 1.125 grams of MSM three times per day for 12 weeks. At 12 weeks, symptoms had worsened by 14 percent in the placebo group, but had improved by 20 percent in the MSM group. Pain had increased by 9 percent in the placebo group, but had decreased by 21 percent in the MSM group. Note that in this 12-week study, users noted no side effects.

A 2006 study also assessed MSM's impact on people with arthritis of the knee, with 25 people receiving a placebo and the other 25 receiving a 3-gram dose of MSM twice a day. At 12 weeks, pain had decreased by 25 percent in the MSM group, and by 13 percent in the placebo group. The physical function of the knee also improved with the use of MSM, but stiffness improved only slightly as compared to the placebo. This higher dose of MSM was associated with the mild side effects of bloating and constipation. One interesting note: The study authors found no change in inflammatory markers with MSM.

Lastly, a 2004 study from India compared the use of MSM, the use of glucosamine, the use of a combination and the use of a placebo for arthritis of the knee. After 12 weeks, patients who took 500 milligrams of MSM three times a day reported a significant reduction in pain and swelling of the knee. This was also seen in the group who took glucosamine. Those who took the combination of both MSM and glucosamine reported an additive benefit in regard to pain and swelling.

Granted, these are small studies, but they do show a slight benefit from MSM, but even milder than from Tylenol or NSAIDs. In these studies, the medication was used every day for 12 weeks, so I would assume that you would have to take MSM daily for a long period to see the benefit.

One important caveat: We don't know if there are any long-term side effects with MSM. If you do try it, start with 500 to 1,000 milligrams three times per day. That dose can be found in any drug or vitamin store.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o Media Relations, UCLA Health, 924 Westwood Blvd., Suite 350, Los Angeles, CA, 90095. Owing to the volume of mail, personal replies cannot be provided.)

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