12(S)-HETE-d8 is primarily used in biomedical research as a stable isotope-labeled internal standard for the quantification of 12(S)-HETE, a bioactive lipid metabolite derived from arachidonic acid. It is particularly valuable in studies focusing on inflammation, cancer, and cardiovascular diseases, where 12(S)-HETE plays a significant role in signaling pathways. Researchers utilize this deuterated compound in liquid chromatography-mass spectrometry (LC-MS) to ensure accurate and precise measurement of endogenous 12(S)-HETE levels in biological samples such as plasma, tissues, or cell cultures. Its application aids in understanding the mechanisms of diseases and evaluating the efficacy of therapeutic interventions targeting lipid metabolism and inflammatory processes.