ColdfX (ginseng extract)

Cold remedies come and go. Airborne, Cold-Eeze, Zicam, homeopathic products, megadoses of vitamin C, and other nostrums have had their day, but flunked in clinical trials, or turned out to help a little but not much—or to have potentially serious side effects. But recently Health Canada (the equivalent of the FDA in the U.S.) put its stamp of approval on Cold-fX, a ginseng-derived product. Ginseng is an herb touted for almost every medicinal purpose imaginable.

Claims, purported benefits: Cold-fX is allowed to claim, at least in Canada, that it "helps reduce the frequency, severity, and duration of cold and flu symptoms by boosting the immune system."

Evidence: The studies on Cold-fX were sponsored by the manufacturer of Cold-fX (just like the studies of most prescription drugs). In one study of healthy middle-aged subjects, those who took Cold-fX over four months had fewer colds, and when they did get colds, symptoms were milder, compared to those taking a placebo. Though the results were encouraging, the Cold-fx studies were small and brief. Still, it is unusual for studies of a "natural product" to be even as well designed as these. Other studies of Cold-fX are underway.

Bottom line: One problem with ginseng on the U.S. market is that you do not really know what kind you are getting. But Cold-fX is a patented, standardized extract of American ginseng root, and studies on Cold-fX have had promising results. You take two tablets of Cold-fX a day over the "long term," presumably throughout the cold season, and a month’s supply costs about $30. Many drugstores in the U.S. sell Cold-fX, but without the claims about reducing cold symptoms. If you want to try Cold-fX, it appears to be safe. But since ginseng has an anticoagulant effect, if you are taking blood thinners (such as warfarin), talk with your doctor before taking Cold-fX.