MSM stands for Methyl Sulfonyl Methane, which is a rich source of organic sulfur. The body uses sulfur to continually create new healthy cells to replace old ones. Without it, the body will produce weak dysfunctional cells. Sulfur deficiencies are associated with slow wound healing, brittle nails and hair, gastrointestinal problems, scar tissue, lung dysfunction, and immune dysfunction. As sulfur in food is lost during processing, deficiencies are very common today. Includes important "How to use" directions.