Methylsulfonylmethane (MSM) is an organosulfur compound with the formula (CH3)2SO2. It is also known by several other names including DMSO2, methyl sulfone, and dimethyl sulfone. This colorless solid features the sulfonyl functional group and is considered relatively inert chemically. It occurs naturally in some primitive plants, is present in small amounts in many foods and beverages, and is marketed as adietary supplement.

Effect on Health:

Stanley W. Jacob reported having administered MSM to over 18,000 patients with a variety of ailments; he co-authored a book promoting MSM with a variety of claims, including its supposed utility as a natural source of "biologically active sulfur," suggesting that people are deficient in such forms of sulfur in their dietary intake. There is no Dietary Reference Intake (DRI) or Daily Value established for sulphur; it is readily available in onions, garlic and cruciferous vegetables and in protein-containing foods, including nuts, seeds, milk and eggs.The claims for the need for sulfur supplementation originate with Robert Herschler, a biochemist who patented "Dietary and pharmaceutical uses of methylsulfonylmethane and compositions comprising it" in 1982;

he claimed that MSM was useful in stress, mucous-membrane inflammation, allergies and gastrointestinal conditions. Registered dietitian Kerry Lang on quackwatch disparages this claim, pointing out:Herschler's patent documents claim that 'the average diet is deficient in methylsulfonylmethane because it is readily lost during conventional food processing, such as frying, dehydrating, dilution with synthetic fillers and other poorly nutritional additives, cooking, radiation or pasteurizing, and long-term storage.' This statement is absurd, because the amount of sulfur in protein foods is not affected by processing. Since Americans tend to consume more protein than they need, 'sulfur deficiency' is very unlikely and would not occur without obvious evidence of severe malnutrition. If it could occur, the remedy would be to eat adequate protein, not to supplement with MSM.MSM is sold as a dietary supplement and marketed with a variety of claims, often in combination with glucosamine and/or chondroitin for helping to treat or prevent osteoarthritis.

According to one review, "The benefits claimed [for MSM] far exceed the number of scientific studies. It is hard to build a strong case for its use other than for treating arthritis problems." The biochemical effects of supplemental methylsulfonylmethane are poorly understood. Some researchers have suggested that MSM has anti-inflammatory effects. The spectrum of biological effects of dimethyl sulfoxide (DMSO) and MSM differ, but those of DMSO may be mediated, at least in part, by MSM.