Echinacea species (including E. purpurea and E. angustifolia).



Echinacea is taken to support the immune system; Tends to increase immune responses

It is traditionally used to maintain, rather than restore, good health; Modern users may apply differently

Echinacea Should not be taken by individuals with autoimmune conditions, or those undergoing immunosuppressive therapy

The root is historically the preferred part,; modern preparations may include root and/or above-ground parts

Clinical Evidence Highlights:

Schoop R, Klein P, Suter A, Johnston S L.  Echinacea in the prevention of induced rhinovirus colds: a meta-analysis. Clinical Therapeutics 2006; 28(2): 174-183.

A systematic review of three placebo-controlled trials suggested that Echinacea extract reduced the chances of experiencing a cold after experimental exposure to rhinovirus. In subjects who did experience a cold, symptoms were not reduced compared to the placebo group.


Shah S A, Sander S, White C M, Rinaldi M, Coleman C I.  Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis. Lancet Infectious Diseases 2007; 7(7): 473-480.

A review of 14 randomized trials (n=1,356 for incidence; n=1,630 for duration) found that treatment with echinacea significantly reduced cold incidence and duration compared with placebo.

Research on the pharmacology of echinacea has mostly focused on a class of xanthic acid derivatives which have been given the name echinacosides. The roots also contain polysaccharides, caffeic acid derivatives, and essential oils including caryophyllene and humulene.
Notes on history of use:
Echinacea is native to the Great Plains region of North America, and as such, its written history of use is limited to the last few centuries.