Rasāyana, रसायन is a Sanskrit word, with literal meaning: Path (āyana) of essence (rasa). It is a term that in early ayurvedic medicine means the science of macrobiotics or lengthening lifespan, and in later (post 8th-century) works sometimes refers to Indian alchemy.
The name of the science of Indian alchemy or proto-chemistry, is more generally "The Science of Mercury", or Rasaśāstra, रसशास्त्र in Sanskrit, Nepali, Marathi, Hindi, Kannada and several other languages. Early Indian alchemical texts discuss the use of prepared forms of mercury or cinnabar (see samskaras). However, there is also ample mention of the preparation of medical tinctures in the early science of Indian alchemy.
Puri has given detailed account of Classical formulations such as Amrit Rasayana, Brahm Rasayana, Jawahar Mohra, Kamdugdha Ras, Laxami Vilas Ras, Laxman Vilas Ras, Madanoday Modak, Makrdhawaj vati, Manmath Ras, Mukta Panchamrit Rasayana, Nari Kalyan Pak, Navjeevan Ras, Navratna Ras, Navratnakalp Amrit, Panchamrit Ras, Paradi Ras, Ramchuramni Ras, Rattivalbh Pak, Shukar Amrit Vati, Smritisagar Ras, Suvarn Malini Vasant, Suvarn Vasant Malti, Swapanmehtank, Vasant Kusmakar Ras, Visha Rasaayana, Vrihda Vangeshwar Rasa.
These classical Rasayan formulas, contain a large number of ingredients, including minerals, pearl, coral and gems, and include a specially processed (samskara) mercury (the word ras indicates mercury as an ingredient). Because of negative publicity and cost factor, the use of the classical rasayana formulas has declined considerably, and most of the preparations available now have herbal ingredients with a couple of mineral and animal products. The non-availability and wild life protection act has made the use of musk, amber, and parts of wild-life animals nearly impossible.
The current Rasayan formulas are based on such ingredients as amla (Emblica officinalis which has very high stable Vitamin C, Vitamin E, and proteins), Terminalia belerica, Terminalia chebula, Shilajit (a mineral exudate high in fulvic acid), Long pepper, Black pepper, Ginger, processed Guggul, Guduchi, Ashwaganda, Shatavari and similar ingredients.
Rasayan has meanings beyond healthful substances. Rasayan Shastr in Ancient India was much less developed than today. Nevertheless, the use and practice of Rasayan was widespread in Ancient India, and some examples of applied rasayan include paints used in the caves of Ajanta and Ellora, Maharashtra state, the steel of Vishnustambha (literal meaning: the tower of Vishnu), and a processed wood sample in the Kondivade caves near the Rajmachi fort in Maharashtra.
According to Multhauf & Gilbert (2008):
The oldest Indian writings, the Vedas (Hindu sacred scriptures), contain the same hints of alchemy that are found in evidence from ancient China, namely vague references to a connection between gold and long life. Mercury, which was so vital to alchemy everywhere, is first mentioned in the 4th- to 3rd-century-BC Artha-śāstra, about the same time it is encountered in China and in the West. Evidence of the idea of transmuting base metals to gold appears in 2nd- to 5th-century-AD Buddhist texts, about the same time as in the West. Since Alexander the Great had invaded India in 325 BC, leaving a Greek state (Gandhāra) that long endured, the possibility exists that the Indians acquired the idea from the Greeks, but it could have been the other way around.
"Something has been said about the chemical excellence of cast iron in ancient India, and about the high industrial development of the Gupta times, when India was looked to, even by Imperial Rome, as the most skilled of the nations in such chemical industries as dyeing, tanning, soap-making, glass and cement... By the sixth century the Hindus were far ahead of Europe in industrial chemistry; they were masters of calcinations, distillation, sublimation, steaming, fixation, the production of light without heat, the mixing of anesthetic and soporific powders, and the preparation of metallic salts, compounds and alloys. The tempering of steel was brought in ancient India to a perfection unknown in Europe till our own times; King Porus is said to have selected, as a specially valuable gift from Alexander, not gold or silver, but thirty pounds of steel. The Moslems took much of this Hindu chemical science and industry to the Near East and Europe; the secret of manufacturing "Damascus" blades, for example, was taken by the Arabs from the Persians, and by the Persians from India."
An 11th-century Persian chemist and physician named Abū Rayhān Bīrūnī reported that "They have a science similar to alchemy which is quite peculiar to them. They call it Rasâyana, a word composed with rasa, i.e., gold. It means an art which is restricted to certain operations, drugs, and compound medicines, most of which are taken from plants. Its principles restore the health of those who were ill beyond hope, and give back youth to fading old age..." Raseśvara, a school of Indian philosophy was focused on finding Moksha: perfection, immortality, liberation using mercury. As such it focuses its efforts on transumation of the human body: from mortal to immortal. Many are the traditional stories of alchemists still alive since time immemorial due to the effects of their experiments. The texts of Ayurvedic Medicine and Science have aspects similar to alchemy: concepts of cures for all known diseases, and treatments that focus on anointing the body with oils.
Since alchemy eventually became engrained in the vast field of Indian erudition, influences from other metaphysical and philosophical doctrines such as Samkhya, Yog, Vaisheshik and Ayurved were inevitable. Nonetheless, most of the Rasayān texts track their origins back to Kaula tantric schools associated to the teachings of the personality of Matsyendranath and the lineage of the Natha Siddhas.
The Rasayān was understood by very few people at the time. Two famous examples were Nagarjunacharya and Nityanadhiya. Nagarjunacharya was a Buddhist monk who, in ancient times, ran the great university of Nagarjun Sagar. His famous book, Rasaratanakaram, is a famous example of early Indian medicine. In traditional Indian medicinal terminology "rus" translates as "mercury" and Nagarjunacharya was said to have developed a method to convert the mercury into gold. Much of his original writings are lost to us, but his teachings still have strong influence on traditional Indian medicine (Ayureveda) to this day.
Rasayana ( Fruit squash or juice )
In many Indian homes, Fruit squash, juices are prepared and served as drink, desert or as accompaniment to meals. In Tulunadu region of India, Banana and Mango Rasayana are made by mixing of fruit pulp with cow's milk or water with thick consistency. This rasayana may be drunk as juice by diluting with water or milk. With thick consistency it is used as accompaniment to Dosa, Chapati or meals. Rasayana is also known as lassi. Many believe this rasayana helps to beat the heat of Indian summer.
- RASAYAN: Ayurvedic Herbs of Rejuvenation and Longevity. Puri, H.S. (2003) Taylor & Francis, London
- Multhauf, Robert P. & Gilbert, Robert Andrew (2008). Alchemy. Encyclopædia Britannica (2008).
- p. 188, Alberuni's India, transl. Edward C. Sachau, vol. 1, London: Trübner & Co., Ludgate Hill, 1888.
- Vayalil PK, Kuttan G, Kuttan R (2002). "Rasayanas: evidence for the concept of prevention of diseases". Am. J. Chin. Med. 30 (1): 155–71. doi:10.1142/S0192415X02000168. PMID 12067090.
- Winston, David & Maimes, Steven. Adaptogens: Herbs for Strength, Stamina, and Stress Relief, Healing Arts Press, 2007. Contains monographs and information on health benefits for the following rasayana herbs that are identified as adaptogens: Amla, Ashwagandha, Guduchi, Holy Basil (tulsi), Shatavari and Shilajit.
- Alan Keith Tillotson Ph.D., A.H.G., D.Ay, (Author), O.M.D., L.Ac., Nai-shing Hu Tillotson (Contributor), M.D., Robert Abel Jr. (Contributor) The One Earth Herbal Sourcebook: Everything You Need to Know About Chinese, Western, and Ayurvedic Herbal Treatments Kensington press, ISBN 978-1-57566-617-4
- Puri, H.S. "RASAYAN: Ayurvedic Herbs for Longevity and Rejuvenation". Taylor & Francis, London, 2003. Gives monographic account and illustrations of 57 plants used as Rasayana in India, along with old as well as new Rasayan formulations.
- Puri, H.S. Ayurvedic Minerals, Gems and Animal Products for Longevity and Rejuvenation. India Book Store, Delhi 2006. Scientific details of all the ingredients other than herb, used as Rasayana in Ayurveda is given. The study on gold, mercury, sulfur, musk and Shilajit are given in good details.
- Anonymus: National Seminar on Rasayana, 8–10 March 1999, Proceedings, Central Council for Research in Ayurveda and Siddha, New Delhi. A very good account of various aspects of RASAYANA by many learned authors.