The lehyas and Rasayanaas are semi solid, generally, pasty materials having both nutritious and curative effects. The product is generally prepared directly from the drug components after powdering them or cooking. The cooked/ powdered materials are mixed with jaggerry and heated slowly for a long time. The final product should have a semisolid/ solid honey type texture and appearance. Ghee, honey, spices etc are also added to the lehya / rasayana at the end of the preparations.
The active principles present in the raw drugs, with or without hydrolytic and pyrrolitic chemical changes get dissolved in the jaggery based rasayanam. Here the starch, protein and also the fat present in the raw materials give texture for the rasayana. Due to the presence of excess sugar of this product, faster absorption of the active principles may be taking place in the biological system because the sugar is known to get absorbed faster . However, available literature gives less information on the clinical study results on the active principles based curative effects of the lehya/ rasayana. Heat and water based changes of the rasayana / lehyas areinevitable because the final products are heated for a long duration for getting the actual paste like product. Inorganic chemicals/salts are also sometimes added as directed in rasachikitsa texts.
Lehas and Rasayanas given in Sahasra Yogam
2. Kooshmaanda leham
3. Maanibhadra leham
6. Draakshaaadi leham
7. Thippalaadi rasaayanam
8. Thiruvruthaadi leham
10. Aswagandhaadi leham
11. Ikshuraadi leham
12. Madhusnuhi rasaayanam 13. Vyoshaadi rasaayanam,,,