Phenol-13C6 is widely used as a stable isotope-labeled compound in various research and analytical applications. It serves as an internal standard in mass spectrometry, particularly in the quantification of phenol and its derivatives in environmental, biological, and chemical samples. This labeling ensures high accuracy and precision in trace analysis by distinguishing the labeled compound from its unlabeled counterpart. Additionally, it is utilized in metabolic studies to track the pathways and transformations of phenol in biological systems. Its application extends to pharmaceutical research, where it aids in drug metabolism and pharmacokinetic studies, providing insights into the behavior of phenolic compounds in the body.