Nature's Bounty supplements are overseen by our scientists, manufacturing specialists and quality experts, each one dedicated to maintaining the highest quality standards. As part of thier commitment to quality, Natures Bounty only uses ingredients from suppliers that meet their stringent Quality Assurance Standards, as well as GMP food quality standards. Every Natures Bounty product is subjected to numerous quality tests and assays throughout the manufacturing process to verify purity and full potency. As an added measure of quality assurance, the initial ingredients, as well as the final product are tested in their microbiological laboratory to make certain that the product is pure and free of harmful bacteria.