(S)-Atenolol-d7 is primarily used in research and analytical applications, particularly as an internal standard in mass spectrometry-based studies. Its deuterated form allows for precise quantification and tracking of atenolol and its metabolites in biological samples, such as blood, urine, or plasma. This is especially valuable in pharmacokinetic and pharmacodynamic studies to understand drug absorption, distribution, metabolism, and excretion. Additionally, it aids in developing and validating analytical methods for detecting atenolol in clinical or forensic settings, ensuring accuracy and reliability in measurements. Its use supports advancements in drug development, therapeutic monitoring, and toxicological investigations.