Skip to Content


Scientific Name(s): Echinacea angustifolia DC, Echinacea pallida (Nutt.) Britton, Echinacea purpurea (L.) Moench
Common Name(s): American coneflower, Black Sampson, Black Susan, Comb flower, Echinacea, Echinaceawurzel, Hedgehog, Igelkopfwurzel, Indian head, Kansas snakeroot, Narrow-leaved purple coneflower, Purple coneflower, Purpursonnenhutkraut, Racine d'echininacea, Radix Echinaceae, Rock-up-hat, Roter sonnenhut, Scurvy root, Snakeroot, Sonnenhutwurzel

Clinical Overview


Although evidence of efficacy in the treatment of infections is limited, use of echinacea as prophylaxis for upper respiratory tract infections has been reported. Use of echinacea for the treatment of anxiety and cancer has been investigated. Specific recommendations for use are unreliable due to variations in the composition of commercial products and inconsistent clinical trial results.


A major limitation of available dosing information is the lack of standardization of echinacea preparations. Commercial preparations contain echinacea components derived from different plant parts, species, and varieties. Recommended dosing includes the following: 300 mg of dry powdered extract (standardized to echinacoside 3.5%), 0.25 to 1.25 mL of liquid extract (1:1 in alcohol 45%), 1 to 2 mL of tincture (1:5 in alcohol 45%), 2 to 3 mL of expressed juice of E. purpurea, and 0.5 to 1 g of dried root or tea (all administered 3 times daily). Long-term use of echinacea or use for longer than 10 days in acute infections in otherwise healthy individuals is not recommended. Parenteral use is not recommended.


Avoid use with known hypersensitivity to plants of the Asteraceae/Compositae family. Echinacea is also contraindicated in patients with rheumatoid arthritis, systemic lupus erythematosus, leukosis, multiple sclerosis, tuberculosis, and HIV infection.


Information regarding safety and efficacy in pregnancy and lactation is lacking. Limited clinical evidence, expert opinion, and long-term traditional use suggest that oral echinacea use is safe during pregnancy at normal dosages. Echinacea should be used with caution during lactation.


Specific case reports of interactions are limited, although one report describes an interaction with etoposide. Data regarding echinacea effects on the cytochrome P450 (CYP-450) enzyme system are conflicting.

Adverse Reactions

Adverse reactions with echinacea are rare. The most commonly reported reactions were allergy, GI upset, and rash. A case report of leukopenia, possibly caused by long-term echinacea use, has been published. Due to conflicting data, echinacea should not be used in any condition potentially affected by immune stimulation or suppression such as HIV, tuberculosis, multiple sclerosis, and immunosuppressive therapy. Use caution in patients with hepatic impairment.


There is little evidence regarding toxicity with echinacea, despite its widespread use. Echinacea has not been associated with acute or chronic toxic effects. Patients with hepatic impairment should use echinacea with caution, as case reports of hepatotoxicity exist.

Scientific Family

  • Asteraceae/Compositae (sunflowers)


Echinacea is a member of the Compositae family (also called the Asteraceae family), which is native to eastern and central North America. "Kansas snakeroot" or "snakeroot" should not be confused with white snakeroot (Ageratina altissima).1 There are at least 9 species of echinacea, with E. purpurea, E. pallida, and E. angustifolia most commonly used for medicinal purposes.1, 2 Because of the difficulty in identifying echinacea species, much of the early European research, particularly on E. angustifolia, may have actually been conducted on E. pallida.3

Echinacea species are perennial herbs that grow up to 1.2 m in height. The plant has narrow leaves and stout stems that blossom into large, solitary flower heads with lavender or purple florets and central rigid bracts. The traditional Radix Echinaceae preparation consists of the fresh or dried roots (either single taproots or fibrous roots) of E. angustifolia.3 When chewed, the root has a pungent taste and causes tingling of the lips and tongue.2, 3 Additional plant parts used include fresh or dried flowering tops and fresh pressed juice from the flowering tops of E. purpurea.


Echinacea is a popular herbal remedy in the United States. The plant was used in traditional medicine by American Indians and was quickly adopted by settlers. During the 1800s, claims for the curative properties of the plant ranged from blood purification to treatment of dizziness and rattlesnake bites. During the early 20th century, extracts of the plant were used as anti-infectives; however, use of these products fell out of favor after the discovery of modern antibiotics. The plant and its extracts continue to be used topically for wound healing and internally to stimulate the immune system.2, 3, 4


The chemical constituents of echinacea are well described; biologically active constituents include a volatile oil (containing pentadecadiene, pentadecene, ketoalkynes, and ketoalkenes), alkamides (mainly a mixture of isobutylamides), polyalkenes, polyalkynes, caffeic acid derivatives, and polysaccharides.2, 3, 4, 5 It has been reported that the alkamides found in echinacea are available following oral administration, but that caffeic acid derivatives are not.4

Toxic pyrrolizidine alkaloids (isotussilagine and tussilagine) have also been identified at low levels.3, 6

Uses and Pharmacology

Methodological concerns, including variations in plant species, plant parts, preparations, and dosages, as well as high dropout rates and a lack of intention-to-treat analyses, make comparisons within individual clinical trials difficult.7, 8


Animal data

Antihyaluronidase activity,9 inhibition of prostaglandins,10, 11 and reduction in proinflammatory mediators in vitro12 and in rodents have been demonstrated.13 When injected intravenously (IV) and applied topically, echinacea inhibited inflammation induced in rodents.14

Clinical data

No clinical data exist regarding the use of echinacea in the management of inflammatory conditions.


Animal data

Root extracts from 3 echinacea species (E. purpurea, E. angustifolia, and E. pallida) produced concentration- and time-dependent induction of apoptosis in human pancreatic and colon cancer cell lines.15 In mice, the mean survival age was prolonged and thymic lymphoma enlargement suppressed with 8 weeks of echinacea therapy; other experiments demonstrated elevated natural killer cell levels and prolonged survival times in leukemic mice.16, 17 In a study in rats, coadministration of cadmium and echinacea led to significantly increased concentrations of cadmium in certain organs and in blood.18 In an in vitro study, typical constituents of echinacea species applied topically were effective in the prevention and/or treatment of skin damage caused by ultraviolet/ultraviolet B radiation. Another study suggested radioprotection following oral administration of echinacea.20

Clinical data

In a trial investigating the effects of an IV-administered polysaccharide fraction of echinacea among 15 patients with advanced gastric cancer, increases in median number of leukocytes occurred; however, the differences were not considered clinically relevant.21 Another study involving 23 patients with tumors showed no effect on cytokine or leukocytes after use of an E. angustifolia preparation.22

CNS effects

Animal data

Anxiolytic activity of echinacea has been demonstrated in limited animal studies.23, 24, 25

Clinical data

An open-label study investigated anxiolytic activity of E. angustifolia extract in healthy individuals (n = 33) with elevated anxiety scores. The study did not include a placebo group, and participants were randomized to 1 or 2 capsules (each capsule containing 20 mg of extract) daily for 1 week. Only the higher dose resulted in a reduction in anxiety scores during treatment and for 2 weeks afterward.26 The observed effect may be due to lipophilic alkylamide constituents interacting with cannabinoid receptors.23


Animal data

Many studies investigating the immunomodulatory properties of various echinacea species, extracts, and plant parts have been conducted. Reviews of the literature generally agree that echinacea extracts exert effects on markers of the immune system.4, 27 In vivo animal studies with negative findings have also been published. In vitro and animal studies are ongoing.28, 29

Clinical data

Clinical studies have been conducted largely in healthy adults10, 30, 31, 32, 33, 34, 35 or to investigate echinacea's potential in preventing or treating specific infections (see Infections/Antimicrobial Effects section).4, 27 Effects such as enhanced macrophage function, stimulation of cytokine production (including certain interleukins and tumor necrosis factor alpha), enhanced natural killer cell function, and increased mean circulating total white blood cell counts have been demonstrated; however, the impact of these effects on clinical outcomes has not been established.4, 27, 36 Reviews note that overt stimulation of immune functions is not without potential for harm4, 27; a case report of potential activation of autoimmune disease (Sjogren syndrome) with echinacea use exists.37

Infections/Antimicrobial effects

Animal data

Antifungal, antibacterial, and antiviral (herpes simplex virus, HIV, and influenza) properties have been studied in vitro4, 38, 39, 40, 41; however, widespread traditional use of echinacea for infections, especially for the common cold, and the availability of clinical trial data make animal data mostly irrelevant.7

Clinical data

According to a Cochrane review of quality clinical trials (conducted up to mid 2013) evaluating echinacea products in the treatment of upper respiratory tract infections, only 1 of 7 studies showed a reduction in duration of infection.7 A pooled analysis was not conducted due to the strong clinical heterogeneity of the studies, which made definitive statements about effects difficult.7, 42 In a clinical trial investigating the effect of echinacea on the severity and recurrence of genital herpes, no difference was observed when compared with placebo.43 A placebo effect was reported in a clinical study using echinacea for treating upper respiratory tract infections,44 and another clinical study suggested an increased risk of disease in echinacea-treated children with otitis media.45

Published reviews of echinacea for infection prevention should be considered separately from those evaluating its role in infection treatment, as prophylactic administration occurs prior to symptom onset and for a longer duration.7, 46 A Cochrane review of quality clinical trials (N = 4,631), including trials published up to mid 2013, evaluating echinacea products in the prevention of upper respiratory tract infections showed a nonsignificant trend in favor of echinacea as prophylaxis; however, the effect size was of limited clinical relevance (10% to 20% relative risk [RR] reduction).7 In a meta-analysis of 6 clinical studies (N = 2,458 patients), 4 evaluating echinacea and 2 evaluating other supplements, the risk for recurrent respiratory infections was reduced with echinacea (RR, 0.649; 95% confidence interval [CI], 0.545 to 0.774; P < 0.0001).46

Performance enhancement

Animal data

The literature includes limited studies evaluating the effects of echinacea on exercise enhancement in animals; however, studies demonstrating anti-inflammatory and antioxidant effects of echinacea have led to supplementation of horse feeds with echinacea products.47

Clinical data

Studies in athletes did not demonstrate enhanced performance or change in hemoglobin concentration with echinacea 8,000 mg daily over 6 weeks.48, 49, 50

According to a consensus statement, there is a lack of evidence supporting use of echinacea in athletes to maintain immune health.36

Other uses

Chicoric acid extracted from E. purpurea was protective against alcohol-induced hepatic steatosis in mice.51

Extracts of the flowering parts of echinacea demonstrated antitussive and bronchodilatory effects in rodents.52

Effects on adipogenesis occurred in vitro, suggesting that extracts of echinacea may have a role in treating obesity or diabetes.53


A major limitation reported in meta-analyses of available trial data was the lack of standardization of echinacea preparations. Many products lacked active echinacea chemical compounds or were contaminated with other chemical entities.4, 7

Recommended dosing includes the following: 300 mg of dry powdered extract (standardized to echinacoside 3.5%), 0.25 to 1.25 mL of liquid extract (1:1 in alcohol 45%), 1 to 2 mL of tincture (1:5 in alcohol 45%), 2 to 3 mL of expressed juice of E. purpurea, and 0.5 to 1 g of dried root or tea (all administered 3 times daily).36 Safety and tolerability have been studied in children with equivocal results.45, 54, 55

Parenteral use is not recommended due to a lack of evidence of safety or effectiveness.7, 21

Long-term use or use for longer than 10 days in acute infections in otherwise healthy individuals is not recommended.56

Pregnancy / Lactation

Information regarding safety and efficacy in pregnancy and lactation is lacking.

A prospective cohort study (N = 206) demonstrated no increased risk of fetal malformations with the use of echinacea during the first trimester57; however, the study was limited by small sample size, allowance of detection of common malformations only, and lack of standardization of preparations.4, 58

Evidence regarding safety of echinacea use during lactation is lacking; a case report documented breast milk concentrations that were similar to serum levels 1 to 4 hours after consumption.59, 60

Despite the Complete German Commission E Compendium Monographs statement that oral echinacea is safe for use during lactation at recommended dosages,61 echinacea should be used with caution during lactation.59, 60, 62

Briggs Book Link


Data regarding effects on the CYP-450 enzyme system are conflicting.63, 64, 65, 66

In 2 small studies, no impact of echinacea on docetaxel67 or etravirine68 pharmacokinetics was found; however, a case report describes an interaction with etoposide.69 Due to upregulation of CYP1A2 (caffeine) and CYP3A4 (midazolam), effects on therapeutic agents such as amitriptyline, haloperidol and olanzapine, theophylline, zileuton, efavirenz and nevirapine, tamoxifen, and etoposide have been suggested.70, 71 Echinacea was less active in inhibiting CYP2C8 enzyme activity (metabolism of antihyperglycemic agents) than were 2 of the other 6 plants tested (ie, cranberry and saw palmetto).72

Clozapine: CYP3A4 inducers (weak) may decrease the serum concentration of clozapine. Monitor therapy.83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93

Etoposide: Echinacea may increase the serum concentration of etoposide. Monitor therapy.94, 95, 96, 97, 98, 99

Etoposide phosphate: Echinacea may increase the serum concentration of etoposide phosphate. Monitor therapy.94, 95, 96, 97, 98, 99

Immunosuppressants: Echinacea may diminish the therapeutic effect of immunosuppressants. Consider therapy modification.100, 101

Nimodipine: CYP3A4 inducers (weak) may decrease the serum concentration of mimodipine. Monitor therapy.102, 103

Adverse Reactions

In reviews and meta-analyses of clinical trials of echinacea in the treatment and prevention of the common cold, allergic reactions, facial edema, and mild transient GI complaints were reportedly the most relevant.7, 46, 81 In trials evaluating echinacea for treatment of the common cold, equal dropout rates due to adverse events were reported for control and treatment arms, whereas in prevention studies, there was a trend toward higher dropout rates due to adverse effects in the treatment arm.7

Echinacea should be used with caution in individuals with hypersensitivity to ragweed, chrysanthemum, marigold, daisies, or related allergens.4, 73, 74

A case report of leukopenia, possibly caused by long-term use of echinacea, has been published.75

Debate exists regarding echinacea use in patients with autoimmune disorders. Until this issue is clarified, echinacea should not be used in any condition potentially affected by immune stimulation or suppression such as HIV, tuberculosis, multiple sclerosis, and immunosuppressive therapy.4, 76 One case report describes potential activation of autoimmune disease (Sjogren syndrome) with echinacea use.37

Patients with hepatic impairment should use echinacea with caution.76 Acute cholestatic hepatitis likely associated with echinacea root tablets (600 mg/day × 5 days) was reported in a 44-year-old healthy Greek male; possible product adulteration was not evaluated.82 In a study of patients with advanced gastric cancer, an association between use of IV E. purpurea extract and the deaths of 2 patients could not be eliminated.21


There is little evidence regarding toxicity with echinacea, despite its widespread use. Echinacea has not been associated with acute or chronic toxic effects.4

Despite low levels of pyrrolizidine alkaloids in echinacea,3, 6 limited case reports describe acute cholestatic hepatitis related to supplementation with echinacea in adults,77, 78 and acute liver failure in a child after 2 weeks of supplementation (total daily echinacea dose of 100.7 mg/day).79 Patients with hepatic impairment should use echinacea with caution.

High-dose oral and IV administration (ie, several times the standard human therapeutic dose) of the expressed juice of E. purpurea to rodents for 4 weeks produced no short-term, genotoxic, carcinogenic, mutagenic, or other toxic reactions.80 However, an association between use of IV E. purpurea extract and the deaths of 2 patients with advanced gastric cancer could not be eliminated.21


1. Echinacea angustifolia USDA, NRCS. 2015. The PLANTS Database (, 9 December 2015). National Plant Data Team, Greensboro, NC 27401-4901 USA.
2. Ross IA. Echinacea angustifolia. In: Ross IA, ed. Medicinal Plants of the World. New York, NY: Humana Press; 2001:119-130.10.1007/978-1-59259-237-1_7
3. Radix Echinaceae. In: WHO Monographs on Selected Medicinal Plants. Vol. 1. Geneva, Switzerland: World Health Organization; 1999.
4. Barnes J, Anderson LA, Gibbons S, Phillipson JD. Echinacea species (Echinacea angustifolia (DC.) Hell., Echinacea pallida (Nutt.) Nutt., Echinacea purpurea (L.) Moench): a review of their chemistry, pharmacology and clinical properties. J Pharm Pharmacol. 2005;57(8):929-954.16102249
5. Duke J. Handbook of Biologically Active Phytochemicals and Their Activities. Boca Raton, FL: CRC Press Inc; 1992.
6. Duke J, Bogenschutz-Godwin M, duCellier J, Duke P. Handbook of Medicinal Herbs. 2nd ed. Boca Raton, FL: CRC Press; 2002.
7. Karsch-Volk M, Barrett B, Kiefer D, Bauer R, Ardjomand-Woelkart K, Linde K. Echinacea for preventing and treating the common cold. Cochrane Database Syst Rev. 2014;2:CD000530.24554461
8. Wolsko PM, Solondz DK, Phillips RS, Schachter SC, Eisenberg DM. Lack of herbal supplement characterization in published randomized controlled trials. Am J Med. 2005;118(10):1087-1093.16194636
9. Facino RM, Carini M, Aldini G, et al. Direct characterization of caffeoyl esters with antihyaluronidase activity in crude extracts from Echinacea angustifolia roots by fast atom bombardment tandem mass spectrometry. Farmaco. 1993;48(10):1447-1461.8117383
10. Guiotto P, Woelkart K, Grabnar I, et al. Pharmacokinetics and immunomodulatory effects of phytotherapeutic lozenges (bonbons) with Echinacea purpurea extract. Phytomedicine. 2008;15(8):547-554.18583121
11. Hinz B, Woelkart K, Bauer R. Alkamides from Echinacea inhibit cyclooxygenase-2 activity in human neuroglioma cells. Biochem Biophys Res Commun. 2007;360(2):441-446.17599805
12. Moazami Y, Gulledge TV, Laster SM, Pierce JG. Synthesis and biological evaluation of a series of fatty acid amides from Echinacea. Bioorg Med Chem Lett. 2015;25(16):3091-3094.26105195
13. Dogan Z, Ergul B, Sarikaya M, et al. The protective effect of Echinacea spp. (Echinacea angustifolia and Echinacea purpurea) in a rat colitis model induced by acetic acid. Pak J Pharm Sci. 2014;27(6):1827-1835.25362606
14. Tubaro A, Tragni E, Del Negro P, Galli CL, Della Loggia R. Anti-inflammatory activity of a polysaccharidic fraction of Echinacea angustifolia. J Pharm Pharmacol. 1987;39(7):567-569.2886631
15. Chicca A, Adinolfi B, Martinotti E, et al. Cytotoxic effects of Echinacea root hexanic extracts on human cancer cell lines. J Ethnopharmacol. 2007;110(1):148-153.17052874
16. Currier NL, Miller SC. Echinacea purpurea and melatonin augment natural-killer cells in leukemic mice and prolong life span. J Altern Complement Med. 2001:7(3):241-251.11439845
17. Miller SC. Echinacea: a miracle herb against aging and cancer? Evidence in vivo in mice. Evid Based Complement Alternat Med. 2005;2(3):309-314.16136209
18. Zitkevicius V, Smalinskiene A, Lesauskaite V, et al. Influence of Echinacea purpurea (L.) Moench extract on the toxicity of cadmium. Ann N Y Acad Sci. 2007;1095:585-592.17404072
19. Facino R, Carini M, Aldini G, Saibene L, Pietta P, Mauri P. Echinacoside and caffeoyl conjugates protect collagen from free radical-induced degradation: a potential use of echinacea extracts in the prevention of skin photodamage. Planta Med. 1995;61(6):510-514.8824943
20. Joksić G, Petrović S, Joksić I, Leskovac A. Biological effects of Echinacea purpurea on human blood cells. Arh Hig Rada Toksikol. 2009;60(2):165-172.19581209
21. 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. Phytother Res. 2002;16(2):138-142.11933115
22. Elsässer-Beile U, Willenbacher W, Bartsch HH, Gallati H, Schulte Mönting J, von Kleist S. Cytokine production in leukocyte cultures during therapy with echinacea extract. J Clin Lab Anal. 1996;10(6):441-445.8951617
23. Sarris J, McIntyre E, Camfield DA. Plant-based medicines for anxiety disorders, part 2: a review of clinical studies with supporting preclinical evidence [published correction appears in CNS Drugs. 2013;27(8):675]. CNS Drugs. 2013;27(4):301-319.23653088
24. Haller J, Hohmann J, Freund TF. The effect of Echinacea preparations in three laboratory tests of anxiety: comparison with chlordiazepoxide. Phytother Res. 2010;24(11):1605-1613.21031616
25. Hájos N, Holderith N, Németh B, et al. The effects of an Echinacea preparation on synaptic transmission and the firing properties of CA1 pyramidal cells in the hippocampus. Phytother Res. 2012;26(3):354-362.21717515
26. Haller J, Freund TF, Pelczer KG, Füredi J, Krecsak L, Zámbori J. The anxiolytic potential and psychotropic side effects of an echinacea preparation in laboratory animals and healthy volunteers. Phytother Res. 2013;27(1):54-61.22451347
27. Barrett B. Medicinal properties of Echinacea: a critical review. Phytomedicine. 2003;10(1):66-86.12622467
28. Torkan S, Khamesipour F, Katsande S. Evaluating the effect of oral administration of Echinacea hydroethanolic extract on the immune system in dog. Auton Autacoid Pharmacol. 2015;35(1-2):9-13.25832590
29. Fonseca FN, Papanicolaou G, Lin H, et al. Echinacea purpurea (L.) Moench modulates human T-cell cytokine response. Int Immunopharmacol. 2014;19(1):94-102.24434371
30. Dapas B, Dall'Acqua S, Bulla R, et al. Immunomodulation mediated by a herbal syrup containing a standardized Echinacea root extract: a pilot study in healthy human subjects on cytokine gene expression. Phytomedicine. 2014;21(11):1406-1410.24877712
31. Ritchie MR, Gertsch J, Klein P, Schoop R. Effects of Echinaforce treatment on ex vivo-stimulated blood cells. Phytomedicine. 2011;18(10):826-831.21726792
32. Brush J, Mendenhall E, Guggenheim A, et al. The effect of Echinacea purpurea, Astragalus membranaceus and Glycyrrhiza glabra on CD69 expression and immune cell activation in humans. Phytother Res. 2006;20(8):687-695.16807880
33. Schwarz E, Parlesak A, Henneicke-von Zepelin HH, Bode JC, Bode C. Effect of oral administration of freshly pressed juice of Echinacea purpurea on the number of various subpopulations of B- and T-lymphocytes in healthy volunteers: results of a double-blind, placebo-controlled cross-over study. Phytomedicine. 2005;12(9):625-631.16194048
34. Coeugniet EG, Elek E. Immunomodulation with Viscum album and Echinacea purpurea extracts. Onkologie. 1987;10(suppl 3):27-33.3309759
35. Hall H, Fahlman MM, Engels HJ. Echinacea purpurea and mucosal immunity. Int J Sports Med. 2007;28(9):792-797.17436202
36. Walsh NP, Gleeson M, Pyne DB, et al. Position statement. Part two: Maintaining immune health. Exerc Immunol Rev. 2011;17:64-103.21446353
37. Logan J, Ahmed J. Critical hypokalemic renal tubular acidosis due to Sjögren's syndrome: association with the purported immune stimulant echinacea. Clin Rheumatol. 2003;22(2):158-159.12740687
38. Cruz I, Cheetham JJ, Arnason JT, Yack JE, Smith ML. Alkamides from Echinacea disrupt the fungal cell wall-membrane complex. Phytomedicine. 2014;21(4):435-442.24252333
39. Sharma M, Anderson SA, Schoop R, Hudson JB. Induction of multiple pro-inflammatory cytokines by respiratory viruses and reversal by standardized Echinacea, a potent antiviral herbal extract. Antiviral Res. 2009;83(2):165-170.19409931
40. Birt DF, Widrlechner MP, Lalone CA, et al. Echinacea in infection. Am J Clin Nutr. 2008;87(2):488S-492S.18258644
41. Sharma M, Schoop R, Suter A, Hudson JB. The potential use of Echinacea in acne: control of Propionibacterium acnes growth and inflammation. Phytother Res. 2011;25(4):517-521.20830697
42. 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 [published correction appears in Lancet Infect Dis. 2007;7(9):580]. Lancet Infect Dis. 2007;7(7):473-480.17597571
43. Vonau B, Chard S, Mandalia S, Wilkinson D, Barton SE. Does the extract of the plant Echinacea purpurea influence the clinical course of recurrent genital herpes? Int J STD AIDS. 2001;12(3):154-158.11231867
44. Barrett B, Brown R, Rakel D, et al. Placebo effects and the common cold: a randomized controlled trial. Ann Fam Med. 2011;9(4):312-322.21747102
45. Wahl RA, Aldous MB, Worden KA, Grant KL. Echinacea purpurea and osteopathic manipulative treatment in children with recurrent otitis media: a randomized controlled trial. BMC Complement Altern Med. 2008;8:56.18831749
46. Schapowal A, Klein P, Johnston SL. Echinacea reduces the risk of recurrent respiratory tract infections and complications: a meta-analysis of randomized controlled trials. Adv Ther. 2015;32(3):187-200.25784510
47. Williams CA, Lamprecht ED. Some commonly fed herbs and other functional foods in equine nutrition: a review. Vet J. 2008;178(1):21-31.17689992
48. Baumann CW, Bond KL, Rupp JC, Ingalls CP, Doyle JA. Echinacea purpurea supplementation does not enhance VO2max in distance runners. J Strength Cond Res. 2014;28(5):1367-1372.24045635
49. Bellar D, Moody KM, Richard NS, Judge LW. Efficacy of a botanical supplement with concentrated Echinacea purpurea for increasing aerobic capacity. ISRN Nutr. 2014;2014:149549.24967264
50. Stevenson JL, Krishnan S, Inigo MM, Stamatikos AD, Gonzales JU, Cooper JA. Echinacea-based dietary supplement does not increase maximal aerobic capacity in endurance-trained men and women. J Diet Suppl. 2016;13(3):324-338.26317662
51. Landmann M, Kanuri G, Spruss A, Stahl C, Bergheim I. Oral intake of chicoric acid reduces acute alcohol-induced hepatic steatosis in mice. Nutrition. 2014;30(7-8):882-889.24985007
52. Capek P, Sutovská M, Kocmálová M, Frañová S, Pawlaczyk I, Gancarz R. Chemical and pharmacological profiles of Echinacea complex. Int J Biol Macromol. 2015;79:388-391.25999016
53. Shin DM, Choi KM, Lee YS, et al. Echinacea purpurea root extract enhances the adipocyte differentiation of 3T3-L1 cells. Arch Pharm Res. 2014;37(6):803-812.24085629
54. Saunders PR, Smith F, Schusky RW. Echinacea purpurea L. in children: safety, tolerability, compliance, and clinical effectiveness in upper respiratory tract infections. Can J Physiol Pharmacol. 2007;85(11):1195-1199.18066121
55. 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. 2003.290(21):2824-2830.14657066
56. Bradley PR, ed. British Herbal Compendium. Vol 1. Bournemouth, England: British Herbal Medicine Association; 1992:81-83.
57. Gallo M, Sarkar M, Au W, et al. Pregnancy outcome following gestational exposure to echinacea: a prospective controlled study. Arch Intern Med. 2000;160(20):3141-3143.11074744
58. Holst L, Wright D, Haavik S, Nordeng H. Safety and efficacy of herbal remedies in obstetrics-review and clinical implications. Midwifery. 2011;27(1):80-86.19782445
59. Sachs HC; Committee On Drugs. The transfer of drugs and therapeutics Into human breast milk: an update on selected topics. Pediatrics. 2013;132(3):e796-e809.23979084
60. Amer MR, Cipriano GC, Venci JV, Gandhi MA. Safety of popular herbal supplements in lactating women. J Hum Lact. 2015;31(3):348-353.25881578
61. Blumenthal M, Goldberg A, Brinckmann J. Herbal Medicine: Expanded Commission E Monographs. Newton, MA: Integrative Medicine Communications; 2000.
62. Perri D, Dugoua JJ, Mills E, Koren G. Safety and efficacy of Echinacea (Echinacea angustafolia, E. purpurea and E. pallida) during pregnancy and lactation. Can J Clin Pharmacol. 2006;13(3):e262-e267.17085774
63. Colombo D, Lunardon L, Bellia G. Cyclosporine and herbal supplement interactions. J Toxicol. 2014;2014:145325.24527031
64. Haefeli WE, Carls A. Drug interactions with phytotherapeutics in oncology. Expert Opin Drug Metab Toxicol. 2014;10(3):359-377.24387348
65. Gorski JC, Huang SM, Pinto A, et al. The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo. Clin Pharmacol Ther. 2004;75(1):89-100.14749695
66. Hansen TS, Nilsen OG. In vitro CYP3A4 metabolism: inhibition by Echinacea purpurea and choice of substrate for the evaluation of herbal inhibition. Basic Clin Pharmacol Toxicol. 2008;103(5):445-449.18947363
67. Goey AK, Meijerman I, Rosing H, et al. The effect of Echinacea purpurea on the pharmacokinetics of docetaxel. Br J Clin Pharmacol. 2013;76(3):467-474.23701184
68. Moltó J, Valle M, Miranda C, Cedeño S, Negredo E, Clotet B. Herb-drug interaction between Echinacea purpurea and etravirine in HIV-infected patients. Antimicrob Agents Chemother. 2012;56(10):5328-5331.22869560
69. Bossaer JB, Odle BL. Probable etoposide interaction with Echinacea. J Diet Suppl. 2012;9(2):90-95.22607644
70. Awortwe C, Manda VK, Avonto C, et al. Echinacea purpurea up-regulates CYP1A2, CYP3A4 and MDR1 gene expression by activation of pregnane X receptor pathway. Xenobiotica. 2015;45(3):218-229.25377539
71. Grappe F, Nance G, Coward L, Gorman G. In vitro inhibitory effects of herbal supplements on tamoxifen and irinotecan metabolism. Drug Metabol Drug Interact. 2014;29(4):269-279.25153228
72. Albassam AA, Mohamed ME, Frye RF. Inhibitory effect of six herbal extracts on CYP2C8 enzyme activity in human liver microsomes. Xenobiotica. 2015;45(5):406-412.25430798
73. Blumenthal M, Busse WR, eds. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Austin, TX: American Botanical Council; 1998.
74. Maskatia ZK, Baker K. Hypereosinophilia associated with echinacea use. South Med J. 2010;103(11):1173-1174.20890257
75. Kemp DE, Franco KN. Possible leukopenia associated with long-term use of Echinacea. J Am Board Fam Pract. 2002:15(5):417-419.12350064
76. Tsai HH, Lin HW, Simon Pickard A, Tsai HY, Mahady GB. Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: a systematic literature review. Int J Clin Pract. 2012;66(11):1056-1078.23067030
77. Gabranis I, Koufakis T, Papakrivos I, Batala S. Echinacea-associated acute cholestatic hepatitis. J Postgrad Med. 2015;61(3):211-212.26119446
78. Kocaman O, Hulagu S, Senturk O. Echinacea-induced severe acute hepatitis with features of cholestatic autoimmune hepatitis. Eur J Intern Med. 2008;19(2):148.18249315
79. Lawrenson JA, Walls T, Day AS. Echinacea-induced acute liver failure in a child. J Paediatr Child Health. 2014;50(10):841.25288248
80. Mengs U, Clare CB, Poiley JA. Toxicity of Echinacea purpurea. Acute, subacute, and genotoxicity studies. Arzneimittelforschung. 1991;41(10):1076-1081.1799389
81. Engebretsen KA, Johansen JD, Thyssen JP. Herbal medicine as a cause of recurrent facial oedema. Contact Dermatitis. 2015;72(5):337-346.25711432
82. Gabranis I, Koufakis T, Papakrivos I, Batala S. Echinacea-associated acute cholestatic hepatitis. J Postgrad Med. 2015;61:211-212.26119446
83. Clozaril (clozapine) [prescribing information]. East Hanover, NJ: Novartis Pharmaceuticals Corp; September 2015.
84. Van Strater AC, Bogers JP. Interaction of St Johns wort (Hypericum perforatum) with clozapine. Int Clin Psychopharmacol. 2012;27(2):121-124.22113252
85. Tiihonen J, Vartiainen H, Hakola P. Carbamazepine-induced changes in plasma levels of neuroleptics. Pharmacopsychiatry. 1995;28(1):26-28.7746842
86. Jerling M, Lindstrom L, Bondesson U, Bertilsson L. Fluvoxamine inhibition and carbamazepine induction of the metabolism of clozapine: evidence from a therapeutic drug monitoring service. Ther Drug Monit. 1994;16(4):368-374.7974626
87. Raitasuo V, Lehtovaara R, Huttunen MO. Effect of switching carbamazepine to oxcarbazepine on the plasma levels of neuroleptics. A case report. Psychopharmacology (Berl). 1994;116(1):115-116.7862923
88. Miller DD. Effect of phenytoin on plasma clozapine concentrations in two patients. J Clin Psychiatry. 1991;52(1):23-25.1988414
89. Peritogiannis V, Pappas D, Antoniou K, Hyphantis T, Mavreas V. Clozapine-rifampicin interaction in a patient with pulmonary tuberculosis. Gen Hosp Psychiatry. 2007;29(3):281-282.17484952
90. Joos AA, Frank UG, Kaschka WP. Pharmacokinetic interaction of clozapine and rifampicin in a forensic patient with an atypical mycobacterial infection. J Clin Psychopharmacol. 1998;18(1):83-85.9472849
91. Muller T, Becker T, Fritze J. Neuroleptic malignant syndrome after clozapine plus carbamazepine. Lancet. 1988;2(8626-8627):1500.2904624
92. Junghan U, Albers M, Woggon B. Increased risk of hematological side-effects in psychiatric patients treated with clozapine and carbamazepine? Pharmacopsychiatry. 1993;26(6):262.8127933
93. Langbehn DR, Alexander B. Increased risk of side-effects in psychiatric patients treated with clozapine and carbamazepine: a reanalysis. Pharmacopsychiatry. 2000;33(5):196.11071023
94. Bossaer JB, Odle BL. Probable etoposide interaction with echinacea. J Diet Suppl, 2012, 9(2):90-95.22607644
95. Penzak SR, Robertson SM, Hunt JD, et al. Echinacea purpurea significantly induces cytochrome P450 3A activity but does not alter lopinavir-ritonavir exposure in healthy subjects. Pharmacotherapy. 2010;30(8):797-805.20653355
96. Gorski JC, Huang SM, Pinto A, et al. The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo. Clin Pharmacol Ther. 2004;75(1):89-100.14749695
97. Hansen TS, Nilsen OG. In vitro CYP3A4 metabolism: Inhibition by Echinacea purpurea and choice of substrate for the evaluation of herbal inhibition. Basic Clin Pharmacol Toxicol. 2008;103(5):445-449.18947363
98. Gurley BJ, Gardner SF, Hubbard MA, et al. In vivo assessment of botanical supplementation on human cytochrome P450 phenotypes: Citrus aurantium, Echinacea purpurea, milk thistle, and saw palmetto. Clin Pharmacol Ther. 2004;76(5):428-440.15536458
99. Yale SH, Glurich I. Analysis of the inhibitory potential of Ginkgo biloba, Echinacea purpurea, and Serenoa repens on the metabolic activity of cytochrome P450 3A4, 2D6, and 2C9. J Altern Complement Med. 2005;11(3):433-439.15992226
100. Stimpel M, Proksch A, Wagner H, et al. Macrophage activation and induction of macrophage cytotoxicity by purified polysaccharide fractions from the plant Echinacea purpurea.Infect Immun. 1984;46(3):845-849.6389368
101. Luettig B, Steinmuller C, Gifford GE, et al. Macrophage activation by the polysaccharide arabinogalactan isolated from plant cell cultures of Echinacea purpurea.J Natl Cancer Inst. 1989;81(9):669-675.2785214
102. Nimodipine [prescribing information]. Montvale, NJ: Ascend Laboratories LLC; April 2015.
103. Tartara A, Galimberti CA, Manni R, et al. Differential effects of valproic acid and enzyme-inducing anticonvulsants on nimodipine pharmacokinetics in epileptic patients. Br J Clin Pharmacol. 1991;32(3):335-340.1777370


This information relates to an herbal, vitamin, mineral or other dietary supplement. This product has not been reviewed by the FDA to determine whether it is safe or effective and is not subject to the quality standards and safety information collection standards that are applicable to most prescription drugs. This information should not be used to decide whether or not to take this product. This information does not endorse this product as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this product. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this product. This information is not specific medical advice and does not replace information you receive from your health care provider. You should talk with your health care provider for complete information about the risks and benefits of using this product.

This product may adversely interact with certain health and medical conditions, other prescription and over-the-counter drugs, foods, or other dietary supplements. This product may be unsafe when used before surgery or other medical procedures. It is important to fully inform your doctor about the herbal, vitamins, mineral or any other supplements you are taking before any kind of surgery or medical procedure. With the exception of certain products that are generally recognized as safe in normal quantities, including use of folic acid and prenatal vitamins during pregnancy, this product has not been sufficiently studied to determine whether it is safe to use during pregnancy or nursing or by persons younger than 2 years of age.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.