FlyerTalk Evangelist
Join Date: Dec 2003
Location: Benicia, California, USA
Programs: AA PLT,AS,UA PP,J6,FB,EY,LH,SQ,HH Dmd,Hyatt Glbl,Marriott Plat,IHG Plat,Accor Gold
Posts: 10,820
This is purely anecdotal, but the couple of times I've felt a cold coming on in the past year I've popped zinc lozenges and doing seems to have stopped the illness. The first time involved a flight. IIRC, I felt the first signs at the end of the flight, then within an hour had a really runny nose, congestion, etc. Got to a friend's place and he gave me a zinc lozenge. The symptoms began to go away within an hour. I took another later that day and then one or two more the next day, and the cold never came back.
Again, just one very minor data point, if it even counts as that. But I thought I'd put it out there.