Can’t say for sure that it works but my son, who use to get sick often has not had a serious illness for nearly one year. The colds or aliments he did have were mild and very brief (1 day). It has not improved his asthma and he still gets occasional croup. Use to have chronic ear infections. Has only had one in the last year (but that could be that he is older). The real test will be through this flu season (he is getting the H1N1 vaccine). So far, I think this product works and I would not do without. My son is 5yrs old and takes 2 tablets q AM about 30/60 minutes before b-fast.