"Rasayana" is Sanskrit term for the body of knowledge developed by ancient sages that covers the subtle essences of nutrients that rejuvenate and restore various organ systems of our bodies. One could say that "rasa" is the illusive fountain of youth or alchemical substance found in certain herbs and foods that have the power to regenerate. In theory, all rasayanas are tonifying and none have either side effects or risks of overdosing. All are believed to enhance clarity, memory, and longevity. Rasayanas might be preserved in ghee or honey, and they rely on a small number of highly revered extraordinary herbs: amla, ashwagandha, bilwa, guduchi, shatavari, tulsi, and some 15-30 more.