About the product WHY MSMPure POWDER? We only use Optimsm which is “the purest MSM on the Planet” and the only MSM made in the USA. Our MSM is the organic form of naturally occurring Sulfur. MSMPure goes through a propriety multi-stage distillation process that ensures a 99.9% pure, third party tested to meet our stringent product specifications. This is the only GRAS-designated, Kosher & Halal certified, non-GMO, gluten-free, allergen-free, non-shellfish-derived, vegan MSM backed by extensive toxicology data.