Used as a stable isotope-labeled internal standard in analytical chemistry, particularly in mass spectrometry and chromatography for the accurate quantification of eugenol in biological samples, essential oils, and pharmaceutical formulations. Its deuterated structure allows clear differentiation from non-labeled eugenol, improving measurement precision and reliability in pharmacokinetic studies, metabolic profiling, and forensic toxicology. Also employed in research settings to trace metabolic pathways and assess the stability and degradation of eugenol-containing products.