MSM is an abbreviation for a naturally occurring compound called methylsulfonylmethane or dimethylsulfone (DMSO2). MSM is a significant source of the element, sulfur, accounting for nearly 34 percent of its entire weight. [1] MSM appears as a white crystalline powder and despite being relatively high in sulfur, MSM has no odor. The compound DMSO is chemically related with MSM; being synthesized via oxidation.

The exact mechanism of action for MSM is not fully known. However, MSM does exhibit mild anti-inflammatory and antioxidant activities which may account for many of its clinical effects. [2] MSM is easily absorbed and enters the bloodstream within hours of consumption. [3] MSM has demonstrated the ability to cross the blood-brain-barrier as evidenced by magnetic resonance spectroscopy (MRS). [4]

MSM may play a role in cancer prevention. MSM has specific effects on cellular proliferation and appears to function in a manner similar to aspirin. A study showed that MSM, when combined with aspirin, induced differentiation by a COX-independent mechanism. [5] The authors suggest that a common mechanism for the chemopreventive action might be the activation of gene functions, leading to differentiation and thereby dismantling the cellular capacity for proliferation.