Medicinal ingredient from natural source. Using a unique process, a special variety of yeast (Saccharomyces cerevisiae) is cultivated on herbs. By the process of fermentation, without the use of heat or chemicals, the yeast cells burst open, releasing their vital elements. To produce the Bio-Strath Tablets, this plasmolysate is then dried and carefully pressed into its final form, the tablet. Free of preservatives and artificial colouring.