Good question. Yes, the beta glucans in this product are derived from yeast, specifically Saccharomyces cerevisiae.

I understand your concern and hope this helps.

For those not concerned with this issue, I love this product and whenever I feel "something coming over me" I take it and begin feeling better within an hour (usually less). Many have been converted to natural health ideas through the use of this combination of herbs.

Nature's Immune Stimulator