Common cold remedies, there is no shortage of them, for sure, but do you know what works and what does not work? Before you pony up for a box of sniffle-stopping supplements, consider what science has to say about popular common cold remedies.

Echinacea Some studies have questioned this herb’s reputation as a cold fighter. But the latest – and largest, with more than 1,300 subjects – review of studies in Lancet Infectious Diseases reports that taking echinacea in pill, tincture, or tea form can reduce your risk of catching a cold by 58 percent.

Ginseng People who popped two 200-milligram capsules of North American ginseng (Panax quinquefolium) daily caught 27 percent les colds than those taking a placebo, found Canadian researchers. As it may interact with some prescription drugs, check with your M.D. before taking the herb.

Vitamin C A review in the Cochrane Library found that taking at least 200 milligrams of the vitamin daily didn’t offer significant protection against a cold. But the same study found that it did reduce cold risk for those who put their bodies under stress, such as marathon runners.

Zinc Researchers at Stanford University found that zinc lozenges didn’t shorten the length or lessen the severity of colds. But nasal swabs containing zinc gel, like those made by Zicam were shown to be effective. Since cold viruses often take root in nasal passages, inhaling zinc may help slow their growth. [via]