Echinacea slightly better than placebo in cold prevention

Reviewers considered 24 randomised controlled trials involving 4300 people.

Individual trials consistently showed positive, but non-significant, trends in prevention – with pooled data showing a 10–20% relative risk reduction – but the potential effects were of “questionable clinical relevance”, the authors said.

There was a trend towards more adverse events in the treatment group, they added.

Out of seven trials examining echinacea as a treatment for colds, only one showed a benefit.