Methyl Sulphonyl Methane

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.[1] 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 a dietary supplement.

Because of its polarity and thermal stability, MSM is used industrially as a high-temperature solvent for both inorganic and organic substances. It is used as a medium in organic synthesis.

MSM and the corresponding sulfoxide dimethyl sulfoxide ((CH3)2SO, DMSO) have different physical properties. MSM is a white crystalline solid at STP (m.p. = 109 °C) whereas DMSO is a liquid under standard conditions. The sulfoxide is a highly polar aprotic solvent and is miscible with water; it is also an excellent ligand.