Taking the herbal remedy echinacea does not reduce the duration or lessen the severity of the common cold, a US study into the effectiveness of the treatment has found.
The research analysed 719 patients aged between 12 to 80 with new-onset common cold. Over five days the patients either took no pills, took echinacea knowingly, or they were blindfolded so they did not know if they were taking echinacea or a placebo.
The study by researchers at the University of Wisconsin found no significant differences in illness duration and severity with the commonly used herbal treatment compared with the placebo.
The team's research paper states: "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.
"However, the trends were in the direction of benefit, amounting to an average half-day reduction in the duration of a week-long cold, or an approximate 10% reduction in overall severity. Our previous research suggests that few people, no more than one in four - would judge this level of benefit worthwhile, given the cost, inconvenience, and possible adverse side-effects."