Dietary Supplement 100% Pure Healthy Joint Function Optimsm ISURA - Non GMO - Mass SPEC - Documentation - Lab Tested Purity & Potency Guaranteed Methyl-sulfonyl-methane (MSM) is a naturally occurring substance known for its diverse health benefits, including support for healthy hair, skin, nails, and joints. Supplementation of MSM is a safe and natural way to optimize your health. Manufactured by Natural Factors to ensure safety and potency in accordance with Good Manufacturing Practices (GMP) of the FDA and Health Canada.