Archives of Current Research International

Chrono-pharmacology (often used interchangeably with chronopharmacology) examines how biological rhythms—especially circadian (≈24-hour) timing—shape drug absorption, distribution, metabolism, excretion, efficacy, and toxicity. This review synthesises contemporary mechanisms linking circadian biology to pharmacokinetics and pharmacodynamics, describes methodological principles for translating circadian insights into clinical dosing strategies, and evaluates evidence across therapeutic domains with an emphasis on cardiovascular, inflammatory, and oncologic applications.  Over the last two decades, advances in molecular chronobiology have clarified that circadian clocks operate not only in the suprachiasmatic nucleus (the central pacemaker) but also in peripheral tissues such as the liver, gut, heart, immune cells, and tumours. These clocks orchestrate rhythmic transcriptional and post-translational programs that create predictable time-of-day variation in drug-processing proteins, target availability, pathway sensitivity, and repair mechanisms. Consequently, “when” a drug is taken can become as clinically meaningful as “which” drug is chosen, particularly for therapies with narrow therapeutic indices or time-sensitive targets. Finally, it outlines emerging technologies enabling individualised chronotherapy, including wearable-derived phase markers, digital phenotyping of sleep–wake behavior, and systems approaches that integrate multi-omics with pharmacology. Chrono-pharmacology reframes therapeutics as a time-aware intervention and offers a pragmatic path to optimise benefit–risk profiles without necessarily changing drug molecules—by aligning dosing with biology.