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This fact sheet provides basic information about echinacea—common names, what the science says, potential side effects and cautions, and resources for more information.
There are nine known species of echinacea, all of which are native to the United States and southern Canada. The most commonly used is Echinacea purpurea. Echinacea has traditionally been used for colds, flu, and other infections, based on the idea that it might stimulate the immune system to more effectively fight infection. Less common folk or traditional uses of echinacea include for wounds and skin problems, such as acne or boils.
The aboveground parts of the plant and roots of echinacea are used fresh or dried to make teas, squeezed (expressed) juice, extracts, or preparations for external use.
What the Science Says
- Study results are mixed on whether echinacea can prevent or effectively treat upper respiratory tract infections such as the common cold. For example, two NCCIH-funded studies did not find a benefit from echinacea, either as Echinacea purpurea fresh-pressed juice for treating colds in children, or as an unrefined mixture of Echinacea angustifolia root and Echinacea purpurea root and herb in adults. However, other studies have shown that echinacea may be beneficial in treating upper respiratory infections.
- NCCIH is continuing to support the study of echinacea for the treatment of upper respiratory infections. NCCIH is also studying echinacea for its potential effects on the immune system.
Side Effects and Cautions
- When taken by mouth, echinacea usually does not cause side effects. However, some people experience allergic reactions, including rashes, increased asthma, and anaphylaxis (a life-threatening allergic reaction). In clinical trials, gastrointestinal side effects were most common.
- People are more likely to experience allergic reactions to echinacea if they are allergic to related plants in the daisy family, which includes ragweed, chrysanthemums, marigolds, and daisies. Also, people with asthma or atopy (a genetic tendency toward allergic reactions) may be more likely to have an allergic reaction when taking echinacea.
- Tell all your health care providers about any complementary health approaches you use. Give them a full picture of what you do to manage your health. This will help ensure coordinated and safe care.
For More Information
The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.
A service of the National Library of Medicine (NLM), PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals.
Office of Dietary Supplements (ODS), National Institutes of Health (NIH)
ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need to Know), fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements), and the PubMed Dietary Supplement Subset.
NIH National Library of Medicine's MedlinePlus
- Barrett BP, Brown RL, Locken K, et al. Treatment of the common cold with unrefined echinacea: a randomized, double-blind, placebo-controlled trial. Annals of Internal Medicine. 2002;137(12):939–946.
- Echinacea. In: Blumenthal M, Goldberg A, Brinckman J, eds. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Lippincott Williams & Wilkins; 2000:88–102.
- Echinacea. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on May 11, 2009.
- Echinacea (E. angustifolia DC, E. pallida, E. purpurea). Natural Standard Database Web site. Accessed at www.naturalstandard.com on June 1, 2009.
- Fugh-Berman A. Echinacea for the prevention and treatment of upper respiratory infections. Seminars in Integrative Medicine. 2003;1(2):106–111.
- O'Neil J, Hughes S, Lourie A, et al. Effects of echinacea on the frequency of upper respiratory tract symptoms: a randomized, double-blind, placebo-controlled trial. Annals of Allergy, Asthma, and Immunology. 2008;100(4):384–388.
- Shah SA, Sander S, White CM, et al. Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis. Lancet Infectious Diseases. 2007;7(7):473–480.
- Taylor JA, Weber W, Standish L, et al. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. Journal of the American Medical Association. 2003;290(21):2824–2830.
- Turner RB, Bauer R, Woelkart K, et al. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. New England Journal of Medicine. 2005;353(4):341–348.
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