Save Your Money: Echinacea doesn't work

According to this article in the New York Times (subscription required):

"Echinacea, the herbal supplement made from purple coneflower and used by millions of Americans to prevent or treat colds, neither prevented colds nor eased cold symptoms in a large and rigorous study.

The study, being published today in The New England Journal of Medicine, involved 437 people who volunteered to have cold viruses dripped into their noses. Some swallowed echinacea for a week beforehand, others a placebo. Still others took echinacea or a placebo at the time they were infected. Then the subjects were secluded in hotel rooms for five days ... [T]he investigators found that those who took echinacea fared no differently from those who took a placebo: they were just as likely to catch a cold, their symptoms were just as severe, they had just as much virus in their nasal secretions..."

I can confirm from my own experience that it doesn't work. Chicken soup, though, is great for a sore throat.