I took this for the first time about three weeks ago. My daughter and sister-in-law had both used it before and recommended it very highly to me. The trick, apparently, is to take it at the very first sign of a cold coming on to prevent it from taking hold. That first time, I was already into a cold for about a day and a half and, while it didn't stop the symptoms, it definitely lessened them and the cold itself was only for a couple of more days. Last week, I started to feel another cold beginning so I took a couple of doses three hours apart. Even though I went to bed that night with a very congested head and sneezing to beat the band, when I woke up the next morning, my head was completely clear and the cold never did develop. I have taken Cold-eze (echinecea and zinc) in the past and thought those worked fairly well, but my recent experience with Airborne has made me a believer. That's going to be my first response from now on. It did upset my stomach a little bit after three doses, but it was worth not having to deal with the nuisance of being a sneezing, coughing fool.