Ineffectiveness of Echinacea for Prevention of Experimental Rhinovirus Colds

The purpose of this study was to assess the effectiveness of echinacea for the prevention of experimental rhinovirus colds. Infection occurred in 44 and 57% and illness occurred in 36 and 43% of the echinacea- and placebo-treated subjects, respectively. This preparation of echinacea had no significant effect on either the occurrence of infection or the severity of illness.