Beta-1,3/1,6-D-Glucan (Beta-Glucans) is a bioactive carbohydrate derived from the cell wall of Saccharomyces cerevisiae, commonly known as Bakers' yeast. Beta-1,3/1,6-D-Glucan supports a healthy immune system through its ability to maintain several aspects of the body's normal immune functions. NOW Extra Strength Beta-Glucans is completed with ImmunEnhancer, a high molecular weight polysaccharide extracted from the larch tree that has been studied for its ability to promote a healthy immune response. Natural color variation may occur in this product. ImmunEnhancer is a trademark of Lonza.