Yeah, I agree that after symptoms present that it's probably too late to do much good. I was taking the same dose mentioned earlier and soon experienced loose bowels. As luck would have it, I had an appointment with my doctor soon after anyway and she laughed and said get off the extra zinc. I'm also on Crestor and that can affect the GI tract so the combination of the two may be what tipped me over the brink. I went back to just taking Zicam at the first sign of symptoms and that does seem to mitigate some of the effects of a cold/flu. I would talk to your doctor before going on a zinc regimen in case there are interactions with other medications you may be taking. Good Luck!