[1',2',3',4',5'-13C5]Thymidine

Isotopic labels can non-invasively track the distribution, transformation and clearance of compounds and their metabolites in the body through techniques such as mass spectrometry (MS) and nuclear magnetic resonance (NMR), which is beneficial to the study of pharmacometabolic kinetics (ADME).
Isotope labeling can reveal specific steps in metabolic pathways. Using compounds with stable isotope labels at specific locations directly in humans or animal models can also help verify drug mechanisms and evaluate unexpected side effects, improving the accuracy and efficiency of clinical research^[3].