Recently when I had a case of acute viral nasopharyngitus (aka rhinitus, aka the common cold), I went to Wegman's to pick up a palliative. The most prominently displayed product, Cold-eeze, didn't look too out of the ordinary, and not feeling well enough to investigate it too closely, I bought a box.

When I got home I read the box to get the directions for the product-- I was surprised to see that the box claimed the Cold-eeze could reduce the length of a cold by about 40%. That seemed to be too good to be true, so I investigated on the internet.

Cold-eeze contains a zinc compound, and there are couple of clinical trials which seem to indicate that this Zinc compound it is effective in reducing the length of a cold.

Another brand of Zinc cold remedy, has faced lawsuits because their product caused customers to lose their sense of smell.

Both of these products are marketed as homeopathic, which I have written about before, which initially concerned me when I saw it on the package.

So, how can a homeopathic product work according to clinical trials?

Well, it's not really homeopathic. Cold-eeze actually contains an appreciable amount of a medicinal compound. The word "homeopathic" is used to draw in people looking for a "natural" cure. Or so some claim.

Lets look at the actual studies. There have only been a few done, and those that have been done were not properly double blinded. How's that? Zinc lozenges taste terrible. When the control and the experimental groups can tell the differences between the lozenge they are given, it is possible for the placebo effect to take place(The Strait Dope).

So the verdict:
There is insufficient evidence that zinc based cold cures work. I'm going to stick with a combo of rest and sudafed.

Works Cited
http://www.straightdope.com/classics/a980206.html