OptiMSM® is manufactured in Washington by Bergstrom Nutrition (formerly Cardinal Nutrition) at a facility that Bergstrom owns and is dedicated only for making MSM. Since theirs is a closed system, things like temperature and humidity are more controlled and theirs is a more consistent product from lot to lot. Their plant is NNFA GMP certified. They also obtain their DMSO from any number of countries. OptiMSM® is also certified as pure and free of contaminants and heavy metals. Bergstrom does pay royalties to the MSM patent holder, MSM Investments Company, LLC., but is not the patent holder itself. Dr. Stanley Jacob, one of the authors of The Miracle of MSM – The Natural Solution for Pain, has given his endorsement to the OptiMSM® brand.