Rich Supply of B-Complex Vitamins Better Digestion, Absorption, Assimilation, and Utilization Enzymatic Digested - B Complex Formula In Shatterproof Bottle Twinlab s Yeast contains a rich supply of B-complex vitamins and natural enzymatic digested yeast in liquid form for better digestion, absorption, assimilation and utilization. Liquid Yeast is a highly concentrated protein source produced from the action of natural enzymes on pure living yeast cells. It contains all the essential amino acids as well as minerals and B-complex vitamins. Since the yeast is enzymatically digested, the nutrients are more readily available to the body than nutrients from other yeasts. The L-Tryptophan in this product is naturally present in the protein. It is not added or manufactured. Questions?