I have been taking this supplement now for some time. It has been great to keep me from colds and flu. Along with immunoplex it’s awesome. I don’t get the usual ‘go around “ colds and flus that everyone seems to get every winter . No coughing , no runny nose, no spending days in bed , none of that crap! I am very busy and that is just NOT something I can be down for days with. So for me this is a must have supplement.