About Herbs, Botanicals & Other Products

Scientific Name
Echinacea purpurea, Echinacea angustifolia, Echinacea pallida
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Common Name

Coneflower, purple coneflower, black Sampson, Sampson root, sonnenhut, igelkopfwurzel

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Brand Name

Echinagard®, Echinacin®

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Clinical Summary

Echinacea purpurea belongs to the family Compositae. Extracts of Echinacea derived from the root and aerial parts of the plant are widely used in Europe and USA to treat common cold. Several large scale randomized controlled trials have been conducted to evaluate Echinacea’s potential but data are conflicting.
Echinacea was shown to stimulate phagocytosis, enhance mobility of leukocytes, stimulate TNF and interleukin 1 secretion from macrophages and lymphocytes, and improve respiratory activity (2) (3) both in vitro and in vivo. The alkylamide, alkaloid, and polyacetylene fractions are thought responsible for such immunomodulatory effects (2).

Data from human clinical trials have shown that it is ineffective in preventing common cold caused by rhinoviruses (4) or in treating upper respiratory infections (5) (6) (16). Studies suggest efficacy of Echinacea/sage spray in treating acute sore throats (17). However, studies on Echinacea’ effect in reducing the incidence and duration of common cold yielded mixed results (7) (8) (9) (10) (22).

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Purported Uses
  • Common cold
  • Immunostimulation
  • Infections
  • Viral infections
  • Wound healing
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Constituents
  • Alkaloids: Isotussilagine, tussilagine
  • Amides: Echinacein, isobutylamides
  • Carbohydrates: Echinacin, polysaccharides (heteroxylan and arabinogalactan), inulin, fructose, glucose, pentose
  • Glycosides: Echinacoside
  • Terpenoids: Germacrane (sesquiterpene lactone ester)
  • Others: Cichoric acid, betaine, methyl-para-hydroxycinnamate, vanillin, phytosterol, volatile oils
    (1)
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Mechanism of Action

Several components in echinacea appear to be responsible for its activity. In vitro and in vivo studies suggest echinacea stimulates phagocytosis, enhances mobility of leukocytes, stimulates TNF and interleukin 1 secretion from macrophages and lymphocytes, and improves respiratory activity (2) (3).

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Warnings

A major concern for research continues to be the lack of standardization between batches as well as the species and the parts of the plant used. An analysis of 59 brand name Echinacea products found that 48% did not contain any Echinacea whereas 10% had no measurable Echinacea. Less than half of the products met the labeled quality standards (1). Commercial products are often mixed with other species including E. angustifolia, and E. pallida.

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Contraindications

Because of a potential for aggravation of underlying disease state, patients with autoimmune disorders such as systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis and other progressive collagenous disorders, tuberculosis, HIV, and AIDS should not consume echinacea.
(15)

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Adverse Reactions
  • Common side effects reported from use of Echinacea are headache, dizziness, nausea, constipation, mild epigastric pain, and rash (5) (11) (12).
  • Less common effects include dermatitis and anaphylaxis (13).
    Reported (oral)
  • A 32-year-old man developed severe thrombotic thrombocytopenic purpura (TTP) following ingestion of Echinacea to alleviate symptoms of an upper respiratory tract infection. The TTP resolved after treatment for a month (18).
  • Consumption of Echinacea resulted in exacerbation of pemphigus vulgaris in a 55-year-old man with a history of the condition, which was controlled with immunesuppressants. Only partial remission was reported after he was treated again with immunesuppressants (19).
  • A 51-year-old woman developed asymptomatic leukopenia following chronic use of echinacea. Her white blood cell count returned to normal levels 7 months after discontinuing Echinacea supplements (20).
  • The National Registry of Drug-Induced Ocular Side Effects received 7 reports of eye irritation and conjunctivitis following use of topical Echinacea. The symptoms resolved after discontinuing Echinacea (21).
  • A case of severe acute hepatitis has been reported following use of Echinacea (23).
  • Hypereosinophilia has been reported in a 58-year-old man following consumption of Echinacea. His symptoms improved after discontinuing Echinacea (24).
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Herb-Drug Interactions
  • Immunosuppressants: Theoretically echinacea may antagonize the effects of immunosuppressants (15).
  • Cytochrome P450 substrates: Echinacea inhibits CYP3A4 and can affect the intracellular concentration of drugs metabolized by this enzyme (14).
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Literature Summary and Critique

Melchart D, et al. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev 2001;4:1-15.
A complete search of the literature was performed and trials conducted in a randomized fashion were included. Sixteen trials were found in the literature, eight studying efficacy as prophylaxis and eight for the treatment of the common cold and viral infections. Echinacea did not exhibit any pooled effect for the prophylaxis of infections when compared to placebo. Trials studying echinacea for the treatment of infections were poorly designed and pooled effects were not able to be determined. The authors state that the variety of products used and lack of consistent evidence indicate further research is necessary. The reported adverse event rate was similar to placebo.

Taylor JA, Weber W, Standish L, Quinn H, Goesling J, McGann M et al. Efficacy and Safety of Echinacea in Treating Upper Respiratory Tract Infections in Children: A Randomized Controlled Trial. JAMA: JAMA 2003;290:2824-30.
A randomized, double-blind, placebo-controlled trial of 407 children between two and 11 years-old. Subjects were randomized to receive Echinacea purpurea (3.75 mL or 5 mL twice daily based on age) or placebo at the onset of upper respiratory track infections (URI). Treatment continued until the cessation of symptoms or until ten days had passed. Findings showed no significant effect of echinacea in primary outcome measures of duration and severity of symptoms, number of days of peak severity, number of days of fever or an overall assessment of severity of symptoms by subjects’ parents. Children in the treatment group were more likely to develop a rash than children taking placebo. Subjects taking echinacea did have a statistically significant reduction in the number of subsequent URIs, although the value of this finding is unclear.

Yale SH, Liu K. Echinacea purpurea Therapy for the Treatment of the Common Cold. Arch Intern Med. 2004;164:1237-1241.
 128 patients participated in this trial of echinacea and upper respiratory tract infections. Patients received either 100 mg of freeze-dried juice of Echinacea purpurea three times a day or placebo. Treatment began within 24 hours of symptom onset and continued until symptoms abated or 14 days had passed. Patients were evaluated by a doctor within 24 hours of starting and completing the trial to verify symptoms. No statistically significant difference was observed between the treatment group and the control for either total symptom score or mean individual symptom score.

Turner R. et al. An Evaluation of Echinacea angustifolia in Experimental Rhinovirus Infections. N Engl J Med. 2005;353(4):341-348.
This is a randomized, placebo-controlled trial on 399 healthy volunteers to study the effects of Echinacea angustifolia extracts as prophylaxis and as treatment for common cold. Some subjects were given either Echinacea extracts or a placebo for seven days before exposure to rhinovirus while others received treatment on the day of exposure. Treatments would continue for 5 more days and the severity of symptoms; viral titers and interleukin-8 in nasal-lavage were measured. The results found no statistically significant difference between the groups that used Echinacea and the groups that used a placebo. The authors concluded that the extracts of E.angustifolia have no effects on common cold caused by rhinovirus.

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References
  1. Gilroy CM, Steiner JF, Byers T, Shapiro H, Georgian W. Echinacea and truth in labeling. Arch Intern Med 2003;163:699-704.
  2. Melchart D, Clemm C, Weber B, et al. Polysaccharides isolated from Echinacea purpurea herba cell cultures to counteract undesired effects of chemotherapy-a pilot study. Phytotherapy Res 2002;16:138-42.
  3. Groom SN, Johns T, Oldfield PR. The potency of immunomodulatory herbs may be primarily dependent upon macrophage activation. J Med Food. Mar 2007;10(1):73-79.
  4. Turner RB, Bauer R, Woelkart K, Hulsey TC, Gangemi JD. An Evaluation of Echinacea angustifolia in Experimental Rhinovirus Infections. N Engl J Med. 2005;353(4):341-348.
  5. 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.JAMA: JAMA 2003;290:2824-30.
  6. Yale SH, Liu K. Echinacea purpurea Therapy for the Treatment of the Common Cold. Arch Intern Med. 2004;164:1237-1241.
  7. Shah SA, Sander S, White CM, Rinaldi M, Coleman CI. Evaluation of echinacea for the prevention and treatment of the common cold: a meta-analysis. Lancet Infect Dis 2007;7(7):473-80.
  8. Schulten B, Bulitta M, Ballering-Bruhl B, Koster U, Schafer M. Efficacy of Echinacea purpurea in patients with a common cold. A placebo-controlled, randomized, double-blind clinical trial. Arzneimittelforschung 2001;51:563-8.
  9. Melchart D, Linde K, Fischer P, Kaesmayr J. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev 2001;4:1-15.
  10. Linde K, Barrett B, Wolkart K, Bauer R, Melchart D. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev. 2006;(1):CD000530.
  11. Giles JT, Palat CT, 3rd, Chien SH, Chang ZG, Kennedy DT. Evaluation of echinacea for treatment of the common cold. Pharmacotherapy 2000;20:690-7.
  12. Grimm W, Muller HH. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med 1999;106:138-43.
  13. Newall C, et al. . Herbal Medicines: A Guide for Health-care Professionals. 1st ed. London: Pharmaceutical Press; 1996.
  14. Scott GN, Elmer GW. Update on natural product-drug interactions. Am J Health-Syst Pharm 2002;59:339-47.
  15. Brinker F. Herb Contraindications and Drug Interactions. 3rd ed. Sandy (OR): Eclectic Medical Publications; 2001.
  16. O’Neil J, Hughes S, Lourie A, Zweifler J. Effects of echinacea on the frequency of upper respiratory tract symptoms: a randomized, double-blind, placebo-controlled trial. Ann Allergy Asthma Immunol. 2008 Apr;100(4):384-8.
  17. Schapowal A, Berger D, Klein P, Suter A. Echinacea/sage or chlorhexidine/lidocaine for treating acute sore throats: a randomized double-blind trial. Eur J Med Res. 2009 Sep 1;14(9):406-12.
  18. Liatsos G, Elefsiniotis I, Todorova R, Moulakakis A. Severe thrombotic thrombocytopenic purpura (TTP) induced or exacerbated by the immunostimulatory herb Echinacea. Am J Hematol. 2006 Mar;81(3):224.
  19. Lee AN, Werth VP. Activation of autoimmunity following use of immunostimulatory herbal supplements. Arch Dermatol. 2004 Jun;140(6):723-7.
  20. Kemp DE, Franco KN. Possible leukopenia associated with long-term use of echinacea. J Am Board Fam Pract. 2002 Sep-Oct;15(5):417-9.
  21. Fraunfelder FW. Ocular side effects from herbal medicines and nutritional supplements. Am J Ophthalmol. 2004 Oct;138(4):639-47.
  22. Barrett B, Brown R, Rakel D, et al. Echinacea for treating the common cold: a randomized trial. Ann Intern Med. 2010 Dec 21;153(12):769-77.
  23. Kocaman O, Hulagu S, Senturk O. Echinacea-induced severe acute hepatitis with features of cholestatic autoimmune hepatitis. Eur J Intern Med. 2008 Mar;19(2):148.
  24. Maskatia ZK, Baker K. Hypereosinophilia associated with echinacea use. South Med J. 2010 Nov;103(11):1173-4.
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How It Works

Bottom Line: Echinacea does not appear to relieve the symptoms of the common cold, but it may shorten the duration of colds when taken within 24 hours of the first cold symptoms.

We do not know exactly how Echinacea works. Echinacea has been studied in the laboratory and with animal subjects. These studies show that different immune cells are stimulated when they are incubated with Echinacea extracts. It is not known whether this same effect occurs in humans. Some compounds found in Echinacea appear to reduce inflammation, relieve pain, and kill bacteria and viruses directly.

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Purported Uses
  • To treat the common cold
    Most clinical trials do not support this use. One clinical trial supports the use of Echinacea for reducing the length of colds, but not the severity of symptoms. 
  • As an antiseptic
    Laboratory studies suggest that Echinacea has anti-bacterial qualities. This use has not been tested in humans in clinical trials.
  • To stimulate the immune system
    Laboratory and animal studies suggest that Echinacea extracts stimulate different parts of the immune system. There is no proof from clinical trials that these effects occur in humans.  
  • To treat viral infections
    Laboratory studies suggest that Echinacea is anti-viral. This use has not been tested in humans other than to treat the common cold.
  • For faster wound healing
    No scientific evidence supports this use.
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Research Evidence

Common cold:
A meta-analysis, which is a complete search of all articles that have been published on a topic, was performed on the effect of echinacea on the common cold. After combining results from available trials, analysts concluded that echinacea did not appear to prevent the onset of the common cold. It was unclear whether echinacea was effective in treating infections because most of the trials examined were designed poorly.

A large scale randomized, placebo-controlled trial was conducted to study the effects of Echinacea angustifolia extracts as prevention and as treatment for common cold. Some subjects were given either the extracts or a placebo before exposing to rhinovirus. Others received treatment on the day of exposure. Treatments would continue for 5 more days and the severity of symptoms and other evidences of immunostimulating activities were measured. The results on 399 volunteers found E.angustifolia is no better than a placebo when used for common cold caused by rhinovirus.

In a clinical trial, echinacea extract or a placebo extract was given to 80 patients twice a day at the first signs of a cold. On average, patients who took echinacea had their cold for a shorter amount of time (six days) compared to patients who took the placebo (nine days), but the groups had equally severe cold symptoms.

In another clinical trial, 128 subjects received either echinacea juice or placebo three times daily within 24 hours of the onset of cold symptoms. Subjects received treatment until the symptoms were relieved or 14 days had passed. Subjects who received echinacea did not have fewer symptoms or shorter symptom duration than those receiving placebo.

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Patient Warnings
  • This product is regulated by the FDA as a dietary supplement. Unlike approved drugs, supplements are not required to be manufactured under specific standardized conditions. The product may not contain the labeled amount or may be contaminated. In addition, it may not have been tested for safety or effectiveness.
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Do Not Take If
  • You are taking immunosuppressants such as tacrolimus or cyclosporine (Echinacea may lessen their effect)
  • You have an autoimmune disorder such as systemic lupus erythematosus or rheumatoid arthritis, multiple sclerosis, other progressive collagenous disorders, tuberculosis, HIV, or AIDS (Echinacea may aggravate the disorder).
  • You are pregnant or nursing
  • If you are taking drugs that are substrates of Cytochrome P450 (Echinacea may increase the risk of side effects of these drugs).
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Side Effects
  • Headache
  • Dizziness
  • Nausea
  • Constipation
  • Mild stomach pain
  • Dermatitis (swelling, irritation and redness of the skin)
  • Anaphylaxis (a serious allergic reaction) has occurred, but rarely.
  • Consumption of Echinacea resulted in exacerbation of pemphigus vulgaris in a 55-year-old man with a history of the condition, which was controlled with immunesuppressants. Only partial remission was reported after he was treated again with immunesuppressants.
  • A 51-year-old woman developed asymptomatic leukopenia following chronic use of echinacea. Her white blood cell count returned to normal levels 7 months after discontinuing Echinacea supplements.
  • The National Registry of Drug-Induced Ocular Side Effects received 7 reports of eye irritation and conjunctivitis following use of topical Echinacea. The symptoms resolved after discontinuing Echinacea.
  • A case of severe acute hepatitis has been reported following use of Echinacea.
  • Hypereosinophilia has been reported in a 58-year-old man following consumption of Echinacea. His symptoms improved after discontinuing Echinacea.
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Special Point
  • Do not use echinacea for more than eight weeks.
  • Echinacea supplements available in stores contain varying amounts and different species of Echinacea. Therefore, the beneficial results seen with Echinacea in clinical trials may not apply to a product that contains a different species or quality of this herb. One recent study found that about half of the Echinacea brands tested did not contain the type or quality of Echinacea that they claimed on the label, so shop with caution.
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Dosage (Inside MSKCC Only)
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Aliases
Coneflower
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E-mail your questions and comments to aboutherbs@mskcc.org.
Last updated: July 26, 2011