The Role of Rasayana Therapy in Cancer Recovery and Immunity Boosting. Rasayana therapy, a key component of Ayurveda, plays a powerful role in cancer recovery and immunity boosting. It focuses on rejuvenation by enhancing cellular repair, reducing treatment side effects, and restoring energy. Rasayana herbs like Ashwagandha, Guduchi, and Amalaki strengthen the immune system, combat oxidative stress, and promote overall well-being.