Displaying 8 results of Estriol Impurities Estriol is a naturally occurring hormone that is used in hormone replacement therapies. During the synthesis of estriol, impurities may be introduced into the final product. These impurities can be harmful if they are present in high concentrations. Therefore, it is important to identify and quantify these impurities to ensure the safety and efficacy of estriol-based treatments. Various analytical techniques can be used to detect and characterize estriol impurities, including chromatography and spectroscopy.