Two species of Echinacea were included in an overview of effectiveness of various substances in preventing and treating colds1.
Analysis of data from 60 studies measuring the effectiveness of Echinacea on the frequency and severity of cold symptoms, so far suggests that only products containing Echinacea Purpurea are promising2. Echinacea Angustifolia root extract, which is also widely used in products intended to prevent colds, is not effective against nasal viruses. It does not reduce the frequency of contracting nasal viruses (rhinovirus type 39) and the severity of its symptoms3.
It is possible that other species of Echinacea may be used for preventive purposes, however their effectiveness is yet to be proven by independent studies2.
- JULIA FASHNER, MD; KEVIN ERICSON, MD; SARAH WERNER, DO.Treatment of the Common Cold in Children and Adults. Am Fam Physician. 2012 Jul 15;86(2):153-159
- Linde K1, Barrett B, Wölkart K, Bauer R, Melchart D.Echinacea for preventing and treating the common cold.Cochrane Database Syst Rev. 2006 Jan 25;(1):CD000530
- Turner RB, Bauer R, Woelkart K, Hulsey TC, Gangemi JD. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. N Engl J Med. 2005 Jul 28;353(4):341-8.