Chronotoxicity evaluates the time-dependent toxicity of xenobiotics together with an individual’s circadian rhythm. Suprachiasmatic nuclei located in the hypothalamus regulate circadian rhythms in individuals. Circadian rhythms are important for human health, metabolic processes, inflammation, and various cancers. This comprehensive review aims to provide an overview of the literature on chronotoxicity, circadian pharmacokinetics, and chronoefficiency. Our literature search was conducted using databases including “Web of Science,” “PubMed,” and “Science Direct.” We used the keywords “circadian rhythm dysregulation,” “chronotoxicity of therapeutics,” “chronotoxicity,” and “time-dependent toxicity” for our literature search. Chronopharmacokinetics studies pharmacokinetic changes related to dosage time. Light plays an important role in circadian rhythm by stimulating ganglion cells. The stimulus is transferred to the suprachiasmatic nuclei and other parts of the brain that regulate the circadian rhythm. Evaluation of the risks and benefits of various therapeutic options requires detailed knowledge of the complex mechanisms that regulate circadian rhythms.