Charaka the ancient authority on Ayurveda defines it as the science of longevity. Rasayana Chikitsa (Rejuvenation therapy) and Vajeekarana Chikitsa (Virilization therapy) constitute two important chapters of the Ashtanga (eight parts) of Ayurveda. According to ancient ayurvedic texts, any aged person who undergoes a six-month course of rejuvenation and virilization known as Kudipraveshika can be transformed into a healthy youth.
The person most suited to undergo this transformation, says Charaka, is “one who has discarded all sins from the heart and strengthened himself with resolution, is full of faith and wishes for the welfare of all beings.”
For the six month course first the body has to be cleansed of all toxins by undergoing the purifying procedures of Panchakarma. After this, the person enters into the Kudi, the special hut, where he/she will undergo treatment under the supervision of an expert physician.
Classical texts provide vivid descriptions of how and where the Kudi is to be built. The place should abound in medicinal herbs and should be inhabited by princes, physicians and Brahmins. The hut should face the east or south and be so designed as to allow the entry of fresh air while excluding direct sunlight and wind.
There has not been any authentic recording of Kudipraveshika therapy in this century.