Lots of people swear by it, as evidenced by its status as Canada's top-selling cold remedy. But does COLD-FX really do what the company claims? Marketplace puts COLD-FX to the test, and discovers that there may be more clever marketing than proven science at the heart of their success. Host Erica Johnson also reveals where the processing of this "Proudly Canadian" product takes place, and speaks with company insiders who reveal a dirty secret. Also, what does Don Cherry have to say?