The influence of the circadian timing system on drug pharmacokinetics significantly impacts the efficacy, adverse effects, and toxicity profiles of various drugs. Moreover, the emergence of sex-related circadian changes in the metabolism and detoxification processes has underscored the importance of considering gender-specific differences in drug tolerability and pharmacology. A better understanding of coupling between central clock and circadian metabolism/transport contributes to the development of more rational drug utilization and the implementation of chronotherapy applications.