Echinacea and the Common Cold

The average cold produces symptoms that last about 6 days.  A popular over-the-counter herbal treatment is echinacea, which has been reported to shorten the severity and duration of symptoms significantly.  Would that this were so!  A recent report, published in the Annals of Medicine, has evaluated the effects of echinacea in a randomized clinical trial.    

The study, which was done in Wisconsin, included over 700 people (aged 12 to 80, 64% female), who had experiencing symptoms that they and the investigators determined were probably due to a common cold virus.  The participants were randomly assigned to one of 4 treatment groups: (1) no pills at all;  (2) pills that the subject knew contained echinacea;  (3) & (4) pills that contained either echinacea or a placebo, but were ‘blinded’, i.e. the subject didn’t know which they contained.  The echinacea dose was equivalent to 10.2 grams of dried echinacea root during the first 24 hours, and then 5.1 grams daily for 4 days.   All the subjects were asked to record their symptoms twice a day for up to 2 weeks. 

The average duration of symptoms was 6.34 days in the blinded echinacea group, 6.76 days in the unblinded echinacea group, 6.87 days in the blinded placebo group, and 7.03 days in the no-pill group.  Total illness duration and symptom severity were not significantly different between echinacea groups and placebo, i.e. they were small and could have occurred by chance alone.  However, trends were in the direction of benefit from the herb, amounting to an average half-day reduction in the duration of a week-long cold. 

We can conclude that this study is unlikely to change people’s minds about whether to take echinacea or not when they get a cold.  If they have received benefit from echinacea in the past, they should continue to take it; if not, there’s no good reason to try it, based on these results.