In another post, I mentioned Airborne (high vitamin dose mixed in water) and Zicam (zinc) spray (not the lozenges)ended my cold 3 days before my wife, who caught it at the same time and did not treat with any nostrum.

I also mentioned I am a big believer in the power of positive thinking- I truly believe that Zicam and Airborne are going to work, while my wife is resigned to riding it out.

I think that's why placebo studies are so prevalent (and so erratic, sometimes)- folks think they're getting a cure, and their belief (or non-belief) affects efficacy.