Aushadha Sevana Kala Revisited: Integrating Agni, Chronopharmacology, and Precision Medicine Through the Agni–Chronopharmacology–Precision Medicine (ACP) Model

Background: Aushadha Sevana Kala (the appropriate timing of medicine administration) is an important yet relatively underexplored principle of classical Ayurvedic therapeutics. Traditional Ayurvedic texts emphasize that the effectiveness of treatment depends not only on the medicinal substance itself but also on factors such as Agni (digestive and metabolic state), patient constitution, disease stage, and the timing of intervention. In parallel, contemporary biomedical disciplines such as chronopharmacology and Precision Medicine have highlighted the importance of biological timing and individual variability in determining therapeutic outcomes. Objective: This narrative review aims to critically examine the classical foundations of Aushadha Sevana Kala, explore its conceptual relationship with Agni, chronopharmacology, and Precision Medicine, and propose an integrative theoretical framework for understanding therapeutic timing in the context of personalized healthcare. Methods: A comprehensive narrative review and conceptual analysis of classical Ayurvedic literature and contemporary biomedical evidence were undertaken. The discussion adopts the principle of functional convergence, emphasizing shared clinical objectives between traditional and modern knowledge systems while avoiding unsupported claims of direct mechanistic or historical equivalence. Results: The review suggests that Aushadha Sevana Kala may be interpreted as a sophisticated clinical strategy for optimizing therapeutic outcomes through the coordinated consideration of metabolic readiness, biological timing, and patient individuality. Agni is reinterpreted as a systems-level representation of functional therapeutic readiness, chronopharmacology contributes to the dimension of temporal physiology, and Precision Medicine provides the framework of individualized therapeutic adaptation. Building upon these complementary perspectives, this review proposes the Agni–Chronopharmacology–Precision Medicine (ACP) Model, in which Aushadha Sevana Kala functions as the practical clinical interface integrating these three domains. Conclusion: The ACP Model offers a novel, hypothesis-generating framework that reinterprets a classical Ayurvedic therapeutic principle through the lens of contemporary personalized and time-sensitive healthcare. By adopting a non-reductionist approach based on conceptual overlap, the model provides a scientifically balanced conceptual bridge between Ayurveda and modern biomedical science and establishes a foundation for future interdisciplinary research in the emerging field of Evidence-Based Precision Ayurveda.