Common Names

  • Coneflower; purple coneflower
  • Black Sampson; Sampson root
  • Sonnenhut
  • Igelkopfwurzel

For Patients & Caregivers

How It Works

Echinacea does not appear to prevent the common cold, but it may shorten the duration of colds or be of benefit in the early treatment of influenza when taken within 24–48 hours of the first symptoms.

Echinacea extract appears to stimulate immune cells in laboratory and animal studies. Some compounds found in echinacea appear to reduce inflammation, relieve pain, and kill bacteria and viruses directly. Human studies have found that echinacea is not effective for preventing the common cold or to treat respiratory infections, but it may shorten the duration of colds. One large clinical trial suggested a specific echinacea formulation was as effective as  a prescription drug to treat influenza, with fewer side effects.

Few studies have been conducted on echinacea with respect to cancer or cancer treatment. Some studies suggest that echinacea could alter the effectiveness of some anticancer drugs or cause adverse effects.

Purported Uses

  • To treat the common cold
    Most studies 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. One large trial suggests a specific echinacea formulation could be as effective as a prescription drug to treat influenza, with fewer side effects.
  • As an antiseptic
    Laboratory studies suggest that echinacea has antibacterial qualities.
  • To stimulate the immune system
    Laboratory and animal studies suggest that echinacea extracts stimulate different parts of the immune system. Human studies suggest immune-changing effects.
  • To treat viral infections
    Laboratory studies suggest that echinacea has antiviral properties and a human study suggests a specific echinacea formulation could be as effective as a prescription drug to treat the influenza virus.
  • For faster wound healing
    Animal models suggest wound-healing properties, but studies have not been conducted in humans.

Do Not Take If

  • You are taking immunosuppressants (eg, tacrolimus, cyclosporine): Echinacea may lessen their effect.
  • You are taking drugs that are substrates of cytochrome P450: Echinacea may increase the risk of side effects of these drugs.
  • You are taking tamoxifen: Lab studies suggest echinacea may weaken the effects of tamoxifen.
  • You are taking etoposide: Echinacea caused low blood platelets in a patient receiving etoposide.
  • You are taking P-glycoprotein (P-gp) substrate drugs: Lab studies suggest echinacea could alter effectiveness of some of these drugs.
  • You are taking oseltamivir: Lab studies showed that echinacea reduced the active formation of this drug, and may therefore reduce effectiveness.
  • You are undergoing eyelid surgery: Echinacea increases the risk of dry eye syndrome.
  • You have allergies or asthma: Allergic reactions have been reported with echinacea.
  • You are pregnant or nursing: Echinacea has not been adequately studied in pregnant women.

Side Effects

Common: Headache, dizziness, nausea, constipation, mild stomach pain, skin rash, irritation

Rare: Serious allergic reactions

Case Reports – Oral
Worsening of a chronic blistering skin disease:
In a 55-year-old man with a history of pemphigus vulgaris, which was controlled with immunosuppressants. Only partial remission was reported after he was treated again with immunosuppressants.

Reduced white blood cell count: In a 51-year-old woman following chronic use of echinacea. Her white blood cell count returned to normal levels 7 months after discontinuing echinacea supplements.

Severe hepatitis: In a 45-year-old man who complained of fatigue and jaundice lasting one week, linked to daily high doses of echinacea used to strengthen his immune system after catching the cold.

Increased eosinophil count in the bloodstream: In a 58-year-old man, there was an increase in this type of white blood cell following use of echinacea. His symptoms improved after discontinuing echinacea.

Low platelet and blood-coagulation disorders: Two case reports involve a 61-year-old cancer patient whose use of echinacea likely interacted with etoposide, and a 32-year-old man who used echinacea to alleviate respiratory symptoms.

Severe acute liver failure: In a 2-year-old girl, likely cause by echinacea toxicity.

Case Report – Topical
Eye irritation and conjunctivitis:
7 reports following use of topical echinacea were received by The National Registry of Drug-Induced Ocular Side Effects. Symptoms resolved after discontinuing echinacea.

Special Point

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 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.

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For Healthcare Professionals

Brand Name

Echinagard®, Echinacin®, Echinaforce® Hotdrink

Scientific Name

Echinacea purpurea, Echinacea angustifolia, Echinacea pallida

Clinical Summary

The genus Echinacea belongs to the family Compositae, commonly referred to as the sunflower family. Of the known species, E. purpurea, E. angustifolia, and E. pallida are commonly used as herbal medicine. Extracts derived from the root and aerial plant parts are widely used in Europe and the United States as nonspecific immunostimulants and to prevent or treat the common cold and influenza. However, natural products have differed greatly in composition (26), mainly due to the use of different species, variable plant materials or extraction methods, and the addition of other components.

In vitro studies suggest immunostimulatory and anti-inflammatory effects (27). A standardized echinacea preparation inactivated influenza viruses (28). In vivo studies suggest it may improve respiratory activity (2) (3). In animal models, echinacea stimulated erythropoiesis, increased blood-oxygen transport (29) (30), produced anxiolytic effects (31), and exhibited wound-healing properties (32) (33) (34).

Data from clinical trials indicate that echinacea is ineffective in preventing the common cold caused by rhinoviruses (4) or in treating upper respiratory infections (5) (6) (16). Studies of its ability to reduce incidence and duration of the common cold yielded mixed results (7) (8) (9) (10) (22) (35) (36). Other analyses do not indicate any benefits for treating colds, and weak evidence for a prophylactic benefit (26) (37), but a large randomized trial found an echinacea formulation to be as effective as oseltamivir for influenza, and with fewer adverse events in the echinacea group (38). A pilot study of a standardized echinacea root extract also suggests immunomodulating activity (39). Another study suggests efficacy of an echinacea/sage spray in treating acute sore throats (17). Preliminary studies on improving or enhancing athletic performance are mixed (40) (41). Very few studies have been conducted on echinacea with respect to cancer or cancer treatment. In vitro, an echinacea extract and its major compound, cichoric acid, exihibited cytotoxic effects in human colon cancer cells (42).

Some studies suggest that echinacea could decrease plasma levels, affect therapeutic efficacy, or cause adverse effects with some anticancer drugs (25) (43). In HIV-infected patients, coadministration of echinacea with etravirine was found to be safe and well tolerated (44). In a large population-based study, use of echinacea was associated with a slight increase in diastolic blood pressure (45). There is insufficient evidence regarding the efficacy and safety of echinacea during pregnancy (46).

Purported Uses

  • Common cold
  • Immunostimulation
  • Viral infections
  • Wound healing

Mechanism of Action

Echinacea’s active constituents include cichoric and caftaric acids, polysaccharides, and alkylamides (47). Immune-modulating effects of a standardized echinacea root extract include upregulation of interleukin (IL)-2 and IL-8 and downregulation of proinflammatory cytokines tumor necrosis factor (TNF)-alpha and IL-6 (39). Immune-modulating effects by alkylamides occur through binding to human cannabinoid receptors 1 and 2, and by inhibiting TNF-alpha (48). Alkylamides may also be responsible for anti-inflammatory effects (27). Although echinacea does not appear to have significant ergogenic or anabolizing effects, it seems to enhance the immune system and decrease oxidative damage (49).

In vitro and in vivo, echinacea extracts were shown to stimulate phagocytosis, enhance mobility of leukocytes, stimulate TNF and IL-1 secretion from macrophages and lymphocytes, and improve respiratory activity (2) (3). However, its effects on innate immunity such as phagocytosis could not be confirmed, and showed only minimal effects on tumor progression, although echinacea did stimulate natural killer cell activity (50). Other studies suggest that bacterial components of echinacea are responsible for immune benefits, as total bacterial load differences and content of bacterial lipopolysaccharides within echinacea samples have correlated with NF-kappaB activation in THP-1 cells (51).

In human colon cancer cells, cichoric acid decreased telomerase activity and induced apoptosis via DNA fragmentation, caspase-9 activation, poly-ADP-ribose polymerase (PARP) cleavage and beta-catenin downregulation (42).

Differential effects of echinacea on intestinal and hepatic CYP3A activities may be due to systemic unavailability of locally-acting constituents that inhibit CYP3A, or rapid absorption of these constituents that limits intestinal exposure and CYP3A induction, or a systemically-formed constituent metabolite that is capable of inducing hepatic but not intestinal CYP3A (52).


  • Patients undergoing chemotherapy should use caution with echinacea, as it may reduce the efficacy of some anticancer medications or cause adverse effects (25) (43) (53).
  • Patients with allergies or asthma should exercise caution with echinacea, as allergic reactions have been reported (54).
  • Patients undergoing blepharoplasty (eyelid surgery), should avoid echinacea because of added increased risk of dry eye syndrome (55).

Adverse Reactions

Common: Headache, dizziness, nausea, constipation, gastrointestinal upset, rash (5) (11) (12) (54)
Rare: Dermatitis, anaphylaxis (13) (54)

Case Reports – Oral
Profound thrombocytopenia: In a 61-year-old man with nonsmall cell lung cancer who was concurrently taking echinacea while receiving chemoradiation with cisplatin and etoposide (25).
Severe thrombotic thrombocytopenic purpura (TTP): In a 32-year-old man following ingestion of echinacea to alleviate upper respiratory tract infection symptoms. TTP resolved after treatment for a month (18).
Pemphigus vulgaris exacerbation: In a 55-year-old man with a history of the condition which was controlled with immunosuppressants. Exacerbation was linked to consumption of echinacea, and only partial remission was regained after he was treated again with immunosuppressants (19).
Asymptomatic leukopenia: In a 51-year-old woman following chronic use of echinacea. Her white blood cell count returned to normal levels 7 months after discontinuing echinacea supplements (20).
Severe acute hepatitis: In a 45-year-old man who complained of fatigue and jaundice lasting one week, linked to the ingestion of daily high doses of echinacea used to strengthen his immune system after catching the cold (23).
Severe acute liver failure: In a 2-year-old girl, likely secondary to echinacea toxicity (56).
Hypereosinophilia: In a 58-year-old man following echinacea consumption, with symptoms improving after discontinuing echinacea (24).

Case Reports – Topical
Eye irritation and conjunctivitis: 7 reports following use of topical echinacea were received by The National Registry of Drug-Induced Ocular Side Effects. Symptoms resolved after discontinuing echinacea (21).

Herb-Drug Interactions

Cytochrome P450 substrates: Echinacea inhibits CYP3A4 and can affect the intracellular concentration of drugs metabolized by this enzyme (14) (43).

Cytochrome P3A or CYP1A2 substrate drugs: Caution should be used when echinacea is coadministered with drugs dependent on CYP3A or CYP1A2 for their elimination (57).

Tamoxifen: In vitro studies suggest concurrent echinacea use may result in subtherapeutic systemic exposure of prodrugs such as tamoxifen, reducing their efficacy (43).

Docetaxel: In a study of cancer patients receiving docetaxel, echinacea at the recommended dosage did not significantly alter docetaxel pharmacokinetics (58) (59).

Etoposide: Echinacea caused profound thrombocytopenia in a patient receiving etoposide, likely due to the inhibition of CYP3A4 (25).

P-glycoprotein (P-gp) substrate drugs: In vitro, echinacea has been shown to inhibit P-gp activity (60), but the clinical significance of this is uncertain as echinacea supplementation in humans did not affect digoxin pharmacokinetics (61).

Oseltamivir: In vitro, echinacea reduced the formation of the active drug and may therefore reduce efficacy, but clinical significance is as yet undetermined (62).

Immunosuppressants: Echinacea may antagonize the effects of immunosuppressants (19).

Dosage (OneMSK Only)


  1. Gilroy CM, Steiner JF, Byers T, Shapiro H, Georgian W. Echinacea and truth in labeling. Arch Intern Med 2003;163:699-704.

  2. 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.

  3. 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.

  4. Yale SH, Liu K. Echinacea purpurea Therapy for the Treatment of the Common Cold. Arch Intern Med. 2004;164:1237-1241.

  5. 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.

  6. 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.

  7. Melchart D, Linde K, Fischer P, Kaesmayr J. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev 2001;4:1-15.

  8. 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.

  9. 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.

  10. Newall C, et al. Herbal Medicines: A Guide for Health-care Professionals. 1st ed. London: Pharmaceutical Press; 1996.

  11. Scott GN, Elmer GW. Update on natural product-drug interactions. Am J Health-Syst Pharm 2002;59:339-47.

  12. Brinker F. Herb Contraindications and Drug Interactions. 3rd ed. Sandy (OR): Eclectic Medical Publications; 2001.

  13. 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.

  14. 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.

  15. 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.

  16. Lee AN, Werth VP. Activation of autoimmunity following use of immunostimulatory herbal supplements. Arch Dermatol. 2004 Jun;140(6):723-7.

  17. 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.

  18. Fraunfelder FW. Ocular side effects from herbal medicines and nutritional supplements. Am J Ophthalmol. 2004 Oct;138(4):639-47.

  19. 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.

  20. 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.

  21. Maskatia ZK, Baker K. Hypereosinophilia associated with echinacea use. South Med J. 2010 Nov;103(11):1173-4.

  22. Bossaer JB, Odle BL. Probable etoposide interaction with Echinacea. J Diet Suppl. 2012 Jun;9(2):90-5.

  23. Karsch-Volk M, Barrett B, Kiefer D, et al. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev. 2014;2:Cd000530.

  24. Goey AK, Rosing H, Meijerman I, et al. The bioanalysis of the major Echinacea purpurea constituents dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides in human plasma using LC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci. Aug 1 2012;902:151-156.

  25. Goel V, Chang C, Slama JV, et al. Alkylamides of Echinacea purpurea stimulate alveolar macrophage function in normal rats. Int Immunopharmacol. Feb 2002;2(2-3):381-387.

  26. Dogan Z, Ergul B, Sarikaya M, et al. The antioxidant effect of Echinacea angustifolia and Echinacea purpurea in rat colitis model induced by acetic acid. Bratisl Lek Listy. 2014;115(7):411-415.

  27. Pazyar N, Yaghoobi R, Rafiee E, et al. Skin wound healing and phytomedicine: a review. Skin Pharmacol Physiol. 2014;27(6):303-310.

  28. Zhai Z, Haney DM, Wu L, et al. Alcohol extract of Echinacea pallida reverses stress-delayed wound healing in mice. Phytomedicine. Jun 2009;16(6-7):669-678.

  29. Allan GM, Arroll B. Prevention and treatment of the common cold: making sense of the evidence. Cmaj. Feb 18 2014;186(3):190-199.

  30. Fashner J, Ericson K, Werner S. Treatment of the common cold in children and adults. Am Fam Physician. Jul 15 2012;86(2):153-159.

  31. Karsch-Volk M, Barrett B, Linde K. Echinacea for preventing and treating the common cold. Jama. Feb 10 2015;313(6):618-619.

  32. Whitehead MT, Martin TD, Scheett TP, et al. Running economy and maximal oxygen consumption after 4 weeks of oral Echinacea supplementation. J Strength Cond Res. Jul 2012;26(7):1928-1933.

  33. Baumann CW, Bond KL, Rupp JC, et al. Echinacea purpurea supplementation does not enhance VO2max in distance runners. J Strength Cond Res. May 2014;28(5):1367-1372.

  34. Grappe F, Nance G, Coward L, et al. In vitro inhibitory effects of herbal supplements on tamoxifen and irinotecan metabolism. Drug Metabol Drug Interact. 2014;29(4):269-279.

  35. Molto J, Valle M, Miranda C, et al. Herb-drug interaction between Echinacea purpurea and etravirine in HIV-infected patients. Antimicrob Agents Chemother. Oct 2012;56(10):5328-5331.

  36. McCarty CA, Berg RL, Rottscheit CM, et al. The use of dietary supplements and their association with blood pressure in a large Midwestern cohort. BMC Complement Altern Med. 2013;13:339.

  37. Dante G, Bellei G, Neri I, et al. Herbal therapies in pregnancy: what works? Curr Opin Obstet Gynecol. Apr 2014;26(2):83-91.

  38. Amico AP, Terlizzi A, Damiani S, et al. Immunopharmacology of the main herbal supplements: a review. Endocr Metab Immune Disord Drug Targets. Dec 2013;13(4):283-288.

  39. Vetvicka V, Vetvickova J. Natural immunomodulators and their stimulation of immune reaction: true or false? Anticancer Res. May 2014;34(5):2275-2282.

  40. Hermann R, von Richter O. Clinical evidence of herbal drugs as perpetrators of pharmacokinetic drug interactions. Planta Med. Sep 2012;78(13):1458-1477.

  41. Mooiman KD, Maas-Bakker RF, Moret EE, et al. Milk thistle’s active components silybin and isosilybin: novel inhibitors of PXR-mediated CYP3A4 induction. Drug Metab Dispos. Aug 2013;41(8):1494-1504.

  42. Huntley AL, Thompson Coon J, Ernst E. The safety of herbal medicinal products derived from Echinacea species: a systematic review. Drug Saf. 2005;28(5):387-400.

  43. Askeroglu U, Alleyne B, Guyuron B. Pharmaceutical and herbal products that may contribute to dry eyes. Plast Reconstr Surg. Jan 2013;131(1):159-167.

  44. Lawrenson JA, Walls T, Day AS. Echinacea-induced acute liver failure in a child. J Paediatr Child Health. Oct 2014;50(10):841.

  45. Gorski JC, Huang SM, Pinto A, et al. The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo. Clin Pharmacol Ther. Jan 2004;75(1):89-100.

  46. Goey AK, Meijerman I, Rosing H, et al. The effect of Echinacea purpurea on the pharmacokinetics of docetaxel. Br J Clin Pharmacol. Sep 2013;76(3):467-474.

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