Study Shows Echinacea Not Effective For The Common Cold

A study shows echinacea not effective for the common cold. 148 college students participated in this experiment at the University of Wisconsin. The researchers wanted to see whether Echinacea was more effective than placebo (“fake pills” with no herb in it). The Annals of Internal Medicine (Ann Intern Med 2002;
137:939-946,1001-1002) published this study recently.

How they did the experiment

The students were given 1 Gram capsules of a mixture of Echinacea herbs that can he bought in health food stores. With the onset of the common cold the students were given 1 capsule 6 times daily for the first day and three times daily from the second to the 10th day. The researchers examined all the students in the placebo group and the Echinacea group for symptoms, duration of the cold and the severity of the cold. The mean duration for both groups was 6 days. None of the criteria in measuring the severity of the cold symptoms were different in both groups. Dr. Barrett, the lead investigator concluded that there was no measurable difference between the two groups, but added that the findings of this trial should not be “the last word” on Echinacea. More studies need to investigate this matter.

Study Shows Echinacea Not Effective For The Common Cold

Study Shows Echinacea Not Effective For The Common Cold


Here is the problems with the study.  The investigators assumed that a placebo pill would not have an effect. However, countless other studies have shown that a placebo often has a 15% to 20% effect. On the other hand it is difficult to have another control for this by not taking any pill. It would be obvious to the subject in the trial that they are the negative control. A negative placebo effect would kick in. So, don’t stop taking Echinacea yet, if you have been taking this normally to treat a common cold. But those of you never took it in the past, you may want to wait first. See what other studies will say in future regarding Echinacea.

Last edited September 16, 2018

About Ray Schilling

Dr. Ray Schilling born in Tübingen, Germany and Graduated from Eberhard-Karls-University Medical School, Tuebingen in 1971. Once Post-doctoral cancer research position holder at the Ontario Cancer Institute in Toronto, is now a member of the American Academy of Anti-Aging Medicine (A4M).