Chronopharmacokinetics is a specialized field within pharmacokinetics that focuses on how the timing of drug administration affects the absorption, distribution, metabolism, and elimination of drugs. The circadian rhythm, governed by the body's biological clock, plays a crucial role in pharmacokinetics, which encompasses the absorption, distribution, metabolism, and elimination of drugs. These pharmacokinetic processes are subject to daily variations influenced by the circadian rhythm. Drug absorption can fluctuate due to changes in gastrointestinal function, such as motility and gastric pH, and blood circulation. Similarly, the distribution of drugs in the body is influenced by factors such as tissue perfusion, plasma protein binding, and cell membrane permeability, all of which are modulated by the circadian rhythm. Metabolism, especially hepatic metabolism, can also experience circadian variations that affect the rate at which drugs are processed and converted into active or inactive metabolites. Finally, the elimination of drugs, primarily through renal function, can show circadian rhythms that impact the excretion of compounds from the body. Understanding these circadian fluctuations is essential to optimize the efficacy and safety of pharmacological treatments, as dosages and administration times could be adjusted to align with the peaks of biological clock activity. Thus, treatments can be more effective and have fewer side effects by leveraging the circadian variability in pharmacokinetic processes.