Displaying 7 results of Quercetin Impurities Quercetin is a flavonoid found in many plants and is known for its antioxidant and anti-inflammatory properties. However, during the production of quercetin, impurities can arise due to the manufacturing process or the source of the plant material. These impurities can affect the purity and quality of the final product, and it is important to monitor and control their levels to ensure the safety and efficacy of quercetin supplements. Some common quercetin impurities include quercetin glycosides, isorhamnetin, and kaempferol.