Solaray Brand Red Yeast Rice is rigorously tested to comply with our Green Screened process to assure the highest quality formula. The Green Screened process means our Red Yeast Rice is tested for impurities and contaminants, including citrinin (**screened using IPLC-MS down to 1 ppm). This stringent screening allows us to offer a pure, high-quality, non-irradiated source of Red Yeast Rice.