Rasāyana (Rejuvenation)

The notion of rejuvenation occurs throughout the Sanskrit corpus in works of āyurveda, yoga, tantra, rasaśāstra (alchemy), each time with a slightly different but related meaning. Within āyurvedic practice, rasāyana refers to rejuvenative practices using various organic materials. How that rejuvenation manifests relies on the nuance of tradition. In the āyurvedic tradition, rasāyana refers to one of the eight subjects of medical specialization. Here rasāyana is vitalization therapy, focused on prolonging one’s life, rejuvenation, anti-aging, and the advancement and preservation of health. These aims are achieved through medical formulations and substances and these therapies are also called rasāyanas (tonics). In the seventh century CE mercury first appeared as a rasāyana ingredient in the Aṣṭāngahṛdayasaṃhitā. By the eleventh century, mercury was commonly found within medical rasāyana therapies. However, rasaśāstra (alchemical) literary works contain chapters on rasāyana therapies within the larger context of iatrochemical procedures and mercury was rarely the central ingredient in these tonics and elixirs. Therefore, rasāyana should not be considered a catch-all term for alchemy. Patañjali’s late-4th- or early-5th-century CE Yogaśāstra and later works on yoga also mention rasāyana formulations, referencing āyurvedic literature though the taking of herbs and medical preparations played only a small role in early yoga practices. Instead, Patañjali and others note rasāyanas are available in the cosmos and the world, where they offer one the ability to overcome old age, death, and attain supernatural powers. The herbs of yogic rasāyana are most often soma and Indian gooseberry (āmalaka). Well-known tantric texts and their commentaries, such as the Tantrāloka, Netratantra, Svacchandatantra, and Kulārṇavatantra, make one or two references to rasāyana but thus far there has been no systematic study on the use of the term within the tantric literary canon.