A Natural Sulfur Nutrient Vita Flex? MSM is pure dietary methylsulfonylmethane, a natural sulfur nutrient. Methylsulfonylmethane is the primary metabolite of DMSO (dimethylsulfoxide). The majority of DMSO absorbed by the horse's tissues is oxidized to form MSM. A form of organic sulfur found in all living organisms, methylsulfonylmethane is a bioavailable source of sulfur, an essential mineral. Pure MSM is an odorless, white crystalline powder that is easy to feed to horses. ? MSM Helping Horses After over a decade of use, MSM is widely acclaimed by veterinarians and horsemen for its contribution to equine health care. Research has shown MSM's importance as a dietary source of sulfur. Sulfur from methylsulfonylmethane is used in the formation of numerous protein-rich structures in the body. ? MSM contributes sulfur to the disulfide bonds that are essential for the proper conformation of hair, horn and connective tissue proteins, such as collagen. Even hormones and antibodies receive sulfur from MSM. L