Bazedoxifene-d4 is a deuterated form of bazedoxifene, primarily used in research and development settings. Its applications include serving as an internal standard in mass spectrometry for the quantification of bazedoxifene in biological samples. This ensures accurate and precise measurement of the drug in pharmacokinetic studies, helping researchers understand its absorption, distribution, metabolism, and excretion. Additionally, it aids in the development of analytical methods for quality control in pharmaceutical formulations. Its use in metabolic studies also provides insights into the drug’s stability and potential interactions, supporting the optimization of therapeutic efficacy and safety.