Cold, Flu, & Cough Health Center

4 Natural Cold Remedies: Do They Work?

You're sneezing. You're sniffling. You're miserable with the cold that won't go away.

And nearly everyone within arm's length is suddenly describing their ''miracle'' cold remedy. They want to tell you all about how you can squash that cold -- maybe overnight! -- if you just (fill in the blank) pop some vitamin C, take echinacea or zinc, or heat up some chicken soup. And they may mention that taking their secret remedy before the first sniffle may have helped you avoid the cold altogether.

Never mind the fervor with which these cold remedies are offered. Do they actually work? WebMD turned to three top experts who have studied the cold virus for decades.

First, the really bad news: "You can't cure a cold," says David A. Blandino, MD, chairman of family and community medicine at the University of Pennsylvania Medical Center Shadyside Hospital in Pittsburgh.

But you may be able to shorten one. Here's the scorecard on whether natural cold remedies such as vitamins and supplements get a thumbs up or thumbs down.

Natural Cold Remedies: The Rundown

1. Zinc. The mineral zinc, available in over-the-counter lozenges, nasal sprays, and gels, may work by preventing the formation of proteins needed by a cold virus to reproduce.

Despite the hoopla about zinc for treatment of colds, scientific studies are scarce, says Jack M. Gwaltney, MD, professor emeritus of internal medicine at the University of Virginia and a longtime cold researcher. Gwaltney tells WebMD that he and his colleagues could find only 14 published studies that looked at zinc the scientific way, with both placebo and treatment groups. Zinc lozenges, they conclude, have no effect. One well-designed study reported a positive effect on treating a cold with zinc nasal gel. But the study results have not yet been replicated, Gwaltney says.

2. Vitamin C. For decades, believers in vitamin C have said taking this vitamin supplement can nip a cold in the bud. The claim is partially triggered by lab studies that find vitamin C affects resistance to virus in animal studies.

But in people? Experts disagree on this slightly but lean toward the negative. Some, including Blandino, say vitamin C has not been proven to shorten the duration of a cold. One 2007 study showed that if vitamin C is taken after a cold begins, it doesn't shorten the cold or make it less severe. But when it is taken daily as a preventive treatment -- not just after that first sniffle -- it can very slightly shorten cold duration, by about 8% in adults and by about 14% in children.

Very highly fit people -- marathon runners, for instance -- might cut their risk of a cold in half by taking the vitamin, the study also showed.

But Gwaltney does not agree. "The weight of scientific evidence and the well-done studies indicate vitamin C does not prevent colds," says Gwaltney. "It may have some mild effect on treating colds."