Are Echinacea products associated with a reduced incidence and a shorter duration of common colds compared with placebo?
Individual prophylaxis trials show no association with prevention of the common cold, but exploratory meta-analysis suggests that Echinacea products may be associated with a small reduction in cold incidence. In treatment trials, there was no association of Echinacea products with a shorter duration of colds.
Karsch-Völk M, Barrett B, Linde K. Echinacea for Preventing and Treating the Common Cold. JAMA. 2015;313(6):618-619. doi:10.1001/jama.2014.17145