Sorafenib-13C d3 is primarily used in research and development as a labeled compound for pharmacokinetic and metabolic studies. Its isotopic labeling allows for precise tracking and quantification of the parent drug, Sorafenib, in biological systems. This compound is particularly valuable in mass spectrometry-based assays, where it serves as an internal standard to enhance the accuracy and reliability of drug concentration measurements in plasma, tissues, or other biological matrices. Additionally, it aids in understanding the drug's absorption, distribution, metabolism, and excretion (ADME) profile, which is critical for optimizing therapeutic efficacy and minimizing adverse effects in clinical applications. Its use is confined to laboratory settings and is not intended for diagnostic or therapeutic purposes.