The researchers studied 719 participants aged 12 to 80 years who had early cold symptoms. Participants were randomly assigned to either no pill, a pill they knew contained echinacea or a pill that could be either echinacea or placebo.
Participants recorded their symptoms twice-daily for approximately 1 week. Those assigned echinacea had a very slight (7-10 hour), statistically insignificant decrease in the duration of their cold symptoms. Similarly, there was no significant decrease in severity of symptoms. The study was funded by the National Center for Complementary and Alternative Medicine of the NIH.
The botanical genus Echinacea is native to North America, and many people use various Echinacea preparations for many illnesses. The results of this study, however, indicate that this dose regimen of the echinacea formulation did not have a large effect on the course of the common cold compared with either blinded placebo or no pills.
As a nurse I am always looking for more natural and less drug centric treatments for maladies. I am still holding out for an earlier published review by the Cochrane Library concluded that echinacea has some benefits, if taken soon enough.