Introduction: Rasayana is a fundamental concept in Ayurveda aimed at promoting longevity, enhancing immunity, and improving overall quality of life. It emphasizes rejuvenation at the level of dhatu (tissues), agni (metabolism), and ojas (vital essence). In the context of increasing lifestyle disorders and aging-related degeneration, Rasayana therapy provides a holistic approach integrating preventive and promotive healthcare. Methods: This work is based on a narrative review of classical Ayurvedic texts such as Charaka Samhita and Sushruta Samhita, along with contemporary interpretations correlating Rasayana with modern concepts like antioxidant activity, immunomodulation, and cellular regeneration. Conceptual analysis was performed to understand its mechanisms and applications in promoting longevity.Results: Rasayana therapy acts through multiple pathways including enhancement of digestion and metabolism (agni), optimization of nutrient assimilation (rasa dhatu formation), and nourishment of subsequent dhatus, ultimately leading to improved ojas. It demonstrates adaptogenic, antioxidant, and immunomodulatory effects, which contribute to delaying aging (jara), preventing disease, and improving cognitive and physical functions. Herbs like Amalaki, Guduchi, and Ashwagandha are widely recognized for their Rasayana properties.Discussion: The concept of Rasayana aligns with modern preventive medicine by targeting cellular health, oxidative stress, and immune resilience. It emphasizes lifestyle modifications, dietary regulation, and herbal interventions as key strategies for healthy aging. Rasayana not only prolongs lifespan but also ensures “healthspan” by maintaining functional efficiency of body systems.