I hear Dr. Dean Adele (sp?) talk about this on the radio a bit ago, at the time they were being forced to change the labeling on their packaging because it is not proven to be effective & the wording was very misleading.

I have pretty good success with zicam, although it doesn't stop every cold, it gets a good 2 out of 3, completely stops them! Trick is..you have to use is the MINUTE you feel the slightest hint of a cold coming on, if you wait too long there isn't much point. Another tip on zicam..at least for the spray..read the directions, you do NOT snort this up your nose! Your spray it in your nose, hold the nostrils together for 5 seconds, then blow it out. I will never forget how bad it hurt when I sucked it up the first time!