Drug ADME experiment in humans is a pivotal drug metabolism study in support of drug development and registration.Human ADME study provides information on the exposure of drug related components, excretion routes of drug-related components (mass balance), and major drug clearance pathway.Radiolabel enables sensitive detection and quantization of drug-related components without synthetic standards.Therefore, radiolabeled drugs have been traditionally employed in human ADME study.However, it is a great challenge to conduct radiolabeled human ADME experiments in China due to special regulatory restriction and cultural difference.The major objective of the current study was to develop an analvtical strategy and decision tree enabling the determination of disposition and mass balance of a non-radiolabeled drug in humans using levo-tetrahydropalmatine (lTHP) as a model compound.