MSM stands for Methyl Sulfonyl Methane and is a supplementary source of sulfur. Sulfur is the third most abundant mineral in the body and is an essential component of many compounds in the body, particularly connective tissue. It has been shown that arthritic cartilage in horses contains one-third less sulfur than normal cartilage and MSM is recommended as a supplement in joint disease in horses. MSM appears to have an anti-inflammatory action and has been shown to reduce symptoms of joint disease in horses and humans. Animal studies have shown that sulphur from oral supplements of MSM is incorporated into body proteins.