Herbal Monograph
Purple coneflower
Echinacea purpurea (L.) Moench
Asteraceae (Compositae)
Widely studied immunomodulating herb for prevention and treatment of upper respiratory infections
Overview
Plant Description
Herbaceous perennial, 60-150 cm tall (typically 60-100 cm in cultivation). Stems erect, green with purple-brown streaks, rough-hairy, occasionally branching. Lower leaves broadly ovate to lanceolate, 3-6 cm wide, with three arching ribs, coarsely toothed margins; upper leaves smaller, sessile. Forms a basal rosette in its first year; flowers only in the second year. Composite flower heads solitary on stem ends, up to 7.5 cm wide. Ray florets 8-21, pink to deep purple, 5-7 cm long, drooping/reflexed. Disk florets tubular, orange-brown to maroon, intermixed with spiny orange-tipped bracts (paleae) -- the 'echinos' (hedgehog) feature giving the genus its name. Blooming period: June-August. Root system: cylindrical taproot with brownish-gray exterior, white interior; fibrous root mass develops with age.
Habitat
Open woods, prairies, and barrens. Prefers well-drained, moist to mesic soils; tolerates drought once established. Full sun to partial shade. Hardy in USDA Zones 3-8.
Distribution
Native to eastern and central North America. Natural range: Michigan to Louisiana, eastward to Virginia and Georgia. Now widely cultivated in North America, Europe (especially Germany), and parts of Australia and New Zealand for commercial herbal production.
Parts Used
Fresh aerial parts (herba recens)
Preferred: Fresh pressed juice (Presssaft); hydroethanolic tincture of fresh herb
Primary medicinal part for E. purpurea specifically. The fresh herb (leaves, stems, flowers) is the basis of the German Commission E positive monograph and the EMA well-established use classification. Fresh pressed juice is the traditional European pharmaceutical form. Most clinical trials used preparations from fresh aerial parts.
Root (radix)
Preferred: Dried root decoction; tincture (1:5, 45% ethanol); standardized dry or liquid extract
Used traditionally and in many commercial preparations. The Commission E issued a negative monograph for E. purpurea root (insufficient evidence at time of review, not for safety reasons). The EMA classified root preparations under 'traditional use' based on 30+ years of documented safe use. Higher alkamide concentration than aerial parts (6.2 vs 1.0 mg/g). Primary part used in North American herbal tradition.
Whole plant (herb + root combined)
Preferred: Combined hydroethanolic extract (e.g., 95% herba, 5% root)
Some commercial preparations combine aerial parts and root. The Echinaforce product (A. Vogel) uses 95% fresh herba and 5% root in ethanolic extraction, and this specific combination was used in the largest clinical trials (Jawad 2012, n=755).
Key Constituents
Alkamides (Alkylamides)
Key immunomodulatory compounds. Root concentration: 6.2 +/- 2.4 mg/g (range 1.2-12.1 mg/g). Aerial parts concentration: 1.0 +/- 0.7 mg/g (range 0.2-3.9 mg/g) (Kraus et al. 2006, PMC1317087). High-quality root: >6 mg/g; minimum marketing standard: >3 mg/g. Absorbed rapidly and detected in plasma within 20 minutes of oral dosing.
Caffeic acid derivatives
Cichoric acid is a primary immunostimulatory and antioxidant compound. Synergistic antioxidant effects when combined with alkamides (Pellati et al. 2006, PMID 16302756). Inhibits hyaluronidase enzyme, which may contribute to wound-healing and anti-inflammatory actions.
Polysaccharides
Most abundant in aqueous extracts and fresh pressed juice. Enhance phagocytosis by macrophages 23-32% at concentrations of 0.01 and 0.001 mg/mL in vitro. Polysaccharides are likely responsible for the immunostimulatory activity of aqueous preparations and pressed juices, while alkamides dominate in ethanolic preparations. Not well absorbed orally; may exert effects via gut-associated lymphoid tissue (GALT).
Glycoproteins (Arabinogalactan-proteins)
Demonstrate complement-stimulating activity in vitro. Bind to lymphocytes, monocytes, and granulocytes (confirmed by flow cytometry). Present primarily in pressed juice and aqueous extracts.
Volatile oils
Approximately 87 compounds identified in steam-distilled essential oil. Sesquiterpene hydrocarbons are the dominant class (70.9% of total). Also contains borneol, caryophyllene epoxide, and limonene. Volatile oil composition profile helps distinguish E. purpurea from other Echinacea species. Source: Ferrante et al. 2023, PMC10647913.
Flavonoids and other phenolics
Minor constituents contributing to overall antioxidant activity. Not considered primary active compounds.
Herbal Actions
Stimulates and enhances immune response
Activates phagocytosis (macrophages, neutrophils), enhances NK cell activity, modulates cytokine production (TNF-alpha, IL-1, IFN-beta). Three mechanisms: phagocytosis activation, fibroblast stimulation, enhanced respiratory burst activity. Well-documented in vitro and in vivo. Alkamides act via CB2 receptor pathway; polysaccharides activate via complement and macrophage pathways.
[1, 2, 19]Modulates and balances immune function
Modulates both innate and adaptive immune responses. Lipophilic alkamide-containing preparations may actually suppress certain overactive immune responses at higher concentrations while stimulating at lower concentrations, making 'immunomodulator' a more accurate term than 'immunostimulant' for ethanolic preparations. This bidirectional activity is the basis for some researchers questioning the autoimmune disease contraindication.
[2, 19, 20]Kills or inhibits the growth of microorganisms
Antiviral activity demonstrated against HSV-1, HSV-2, and influenza viruses in vitro. Selective antibacterial activity. Jawad 2012 trial showed significant prevention of virally confirmed colds, especially enveloped virus infections (P < 0.05). Antifungal activity also reported.
[8, 20]Prevents or slows oxidative damage to cells
Cichoric acid and alkamides demonstrate synergistic antioxidant effects in vitro, including inhibition of LDL oxidation. Secondary to primary immunomodulatory actions.
[21]Gradually restores proper body function and increases overall health
Eclectic medicine classification. King's American Dispensatory: 'an alterative, exerting an influence over the secretory and lymphatic functions, which is unsurpassed by few, if any other of the known alteratives.' Traditional action; not validated by modern pharmacological study under this classification.
[15]Therapeutic Indications
Respiratory System
Common cold -- treatment (reduced severity and duration)
EMA well-established use classification for herba recens (oral, short-term treatment). Shah 2007 meta-analysis: 58% reduced odds of developing cold, 1.4-day reduction in duration. Schulten 2001: median illness 6 days vs 9 days (P=0.0112). Barrett 2010: trend toward benefit but not statistically significant (P=0.089). Cochrane 2014: some products may show weak benefit but clinical relevance unclear. Product and preparation quality appears to be critical variable.
[2, 7, 9, 11, 13]Common cold -- prevention
EMA well-established use classification for herba recens (oral, short-term prevention). Jawad 2012 (n=755): reduced total cold episodes and cumulated episode days over 4-month prophylaxis; especially effective against enveloped virus infections (P < 0.05). Cochrane 2014: none of 12 prevention comparisons reached statistical significance individually. Exploratory meta-analyses suggest 10-20% relative risk reduction.
[2, 8, 9]Recurrent upper respiratory tract infections
Commission E approved indication (recurrent infections of the respiratory tract). Schapowal 2015 meta-analysis of 6 RCTs (n=2458): reduced risk of recurrent RTIs (RR 0.649, 95% CI 0.545-0.774, P < 0.0001). In high-susceptibility individuals: RR 0.501. Complications (pneumonia, otitis media, tonsillitis) also reduced (RR 0.503). Ethanolic extracts appeared superior to pressed juices.
[1, 12]Immune System
Immunostimulation / immune support
Strong in vitro and in vivo pharmacological evidence for activation of macrophage phagocytosis, NK cell activity, and cytokine modulation. Clinical evidence is indirect (through cold prevention/treatment outcomes). Commission E: supportive therapy for infections. WHO: supportive therapy for colds and infections of the upper respiratory tract.
[1, 4, 19]Urinary System
Recurrent lower urinary tract infections
Commission E approved indication (recurrent infections of the urinary tract). Listed in ESCOP herba monograph. Minimal specific clinical data for this indication; classification based primarily on traditional use and theoretical immunostimulatory mechanism.
[1]Skin / Integumentary
Mild acne (topical application, root preparations)
EMA traditional use classification for radix preparations applied topically. Limited evidence; based on long-standing traditional use.
[3]Energetics
Temperature
cool
Moisture
slightly dry
Taste
Tissue States
hot/excitation, damp/stagnation
King's American Dispensatory (Felter & Lloyd, 1898) classifies Echinacea as bitter, pungent, and cool, acting on the lungs, stomach, blood, and liver. The characteristic acrid tongue-tingling paresthesia is caused by alkamides and is used as a quality indicator for potent preparations. Indicated for conditions presenting with signs of heat and infection/sepsis. Eclectic tradition: clears heat from lungs, stomach, and blood, helping to purify 'bad blood.' Some modern Western herbalists classify E. purpurea as slightly more neutral/balanced than E. angustifolia. CAVEAT: Herbal energetics are interpretive frameworks within Western herbalism, not standardized across all practitioners.
Traditional Uses
Native American (Cheyenne)
- Sore mouth and gums (tea of leaves and roots)
- Sore neck
- Toothache (root chewed or applied)
- Rheumatism and arthritis
- Mumps and measles (tea)
- Chewed root as sialagogue during Sun Dance to prevent thirst
[17]
Native American (Lakota/Oglala)
- Analgesic for toothache
- Wound poultice
- Snakebite antidote
"Lakota name: Ichahpe hu. Note: The primary species used by the Lakota was E. angustifolia, native to the Great Plains, not E. purpurea."
Native American (Comanche)
- Sore throat
- Toothache
"The Comanche intentionally scattered E. angustifolia seeds across their hunting grounds (from Wyoming to Texas) to ensure availability of this important medicine."
Native American (other tribes)
- Coughs (Choctaw)
- Colds (Crow)
- Venereal diseases (Delaware)
- General medicine, wound dressing, snakebite (Omaha -- one of most important medicinal plants)
- Various medicinal uses (Kiowa)
"General Native American preparations: root chewed for toothache and sore throat; root poultice applied to wounds, swellings, sores, and snakebites; root decoction used as wash for burns. Most documented Native American use involves E. angustifolia (the prairie species), which was the primary species in Great Plains traditions."
Eclectic medicine (1880s-1930s)
- Blood purifier / alterative
- Snakebite and venomous bites
- Septicemia and blood poisoning
- Syphilis and other venereal diseases
- Typhus
- Diphtheria and scarlet fever
- Septic wounds
- Dysentery
- Cancer (chronic use)
- Chronic mastitis
- Chronic ulceration
- Tubercular abscesses
- Chronic glandular indurations
- Migraines
- Rheumatism
"King's American Dispensatory (Felter & Lloyd, 1898): '[Echinacea] is an alterative, exerting an influence over the secretory and lymphatic functions, which is unsurpassed by few, if any other of the known alteratives.' Dr. H.C.F. Meyer of Pawnee City, Nebraska, introduced Echinacea to the Eclectic medical profession in the 1880s, claiming it as a remedy for rattlesnake bites and various infections. Lloyd Brothers manufactured 'Specific Medicine Echinacea' and 'Echafolta' -- among the most widely used Eclectic preparations."
Modern Research
Meta-analysis of echinacea for common cold prevention and treatment
Meta-analysis of 14 unique studies (1,356 participants for incidence, 1,630 for duration) evaluating echinacea's effect on common cold incidence and duration.
Findings: Echinacea decreased odds of developing common cold by 58% (OR 0.42, 95% CI 0.25-0.71; P < 0.001) and reduced cold duration by 1.4 days (WMD -1.44, 95% CI -2.24 to -0.64; P = 0.01). Products based on E. purpurea aerial parts in 22% alcohol extract (Echinaguard/Echinacin) showed 56% incidence reduction.
Limitations: Significant heterogeneity in preparations, doses, and study designs. Potential publication bias. Different Echinacea species and plant parts were pooled together.
[7]
Large-scale prevention trial of E. purpurea extract (Echinaforce)
Largest Echinacea prevention trial. 755 healthy subjects received either E. purpurea extract (95% herba, 5% root in ethanolic extraction; 2400 mg/day) or placebo over 4 months.
Findings: Echinacea reduced total number of cold episodes, cumulated episode days within the group, and painkiller-medicated episodes. Inhibited virally confirmed colds, especially enveloped virus infections (P < 0.05). Safety noninferior to placebo (adverse events 9-10% in both groups).
Limitations: Single product tested (Echinaforce, A. Vogel). Compliance-dependent results. Self-reported primary outcomes. Lead author affiliation with product manufacturer.
[8]
Cochrane systematic review of echinacea for the common cold
Comprehensive Cochrane systematic review including 24 double-blind RCTs with 4,631 participants across 33 comparisons of echinacea preparations and placebo.
Findings: None of 12 prevention comparisons reporting number of patients with at least one cold episode found a statistically significant difference. Treatment results were 'weak' overall. Exploratory meta-analyses suggest some E. purpurea-based products may reduce relative risk of catching a cold by 10-20%, though clinical relevance is unclear.
Limitations: Great heterogeneity of preparations makes comparison across trials very difficult. Many studies had methodological weaknesses. Results cannot be generalized from one echinacea product to another.
[9]
Standardized E. purpurea extract (Echinilin) for common cold treatment
RCT of standardized extract containing 0.25 mg/mL alkamides, 2.5 mg/mL cichoric acid, and 25 mg/mL polysaccharides. 282 subjects enrolled; 128 developed colds (59 echinacea, 69 placebo).
Findings: Total daily symptom scores 23.1% lower in echinacea group (P < 0.01). Response rate consistently greater in echinacea group throughout treatment period. Minimal adverse effects.
Limitations: Single product. Relatively small number who developed colds (128 of 282 enrolled). Industry-funded study.
[10]
E. purpurea pressed juice for common cold treatment
RCT of 80 adults with early cold symptoms receiving pressed juice of E. purpurea aerial parts or placebo. Conducted in industrial plant setting for rapid treatment initiation.
Findings: Median illness duration significantly shorter in echinacea group: 6.0 days vs 9.0 days in placebo group (P = 0.0112). Well-tolerated.
Limitations: Small sample size (n=80). Single-center. Industry involvement (Madaus AG). Single preparation tested.
[11]
Meta-analysis of echinacea for recurrent respiratory infections and complications
Meta-analysis of 6 high-quality RCTs (Jadad score >= 4) with 2,458 participants studying echinacea for prevention of recurrent RTIs.
Findings: Echinacea reduced risk of recurrent RTIs (RR 0.649, 95% CI 0.545-0.774, P < 0.0001). In high-susceptibility individuals with stress or immunological weakness: RR 0.501 (95% CI 0.380-0.661, P < 0.0001). Complications including pneumonia, otitis media/externa, and tonsillitis/pharyngitis also reduced (RR 0.503, 95% CI 0.384-0.658, P < 0.0001). Ethanolic extracts appeared superior to pressed juices.
Limitations: Lead author (Schapowal) affiliated with A. Vogel. Predominantly Echinaforce product studied across included trials. Moderate statistical heterogeneity.
[12]
E. purpurea/angustifolia for common cold treatment (negative trial)
Large RCT (n=719, ages 12-80) with 4 parallel groups: no pills, blinded placebo, blinded echinacea, open-label echinacea. Used dried root extract of E. purpurea + E. angustifolia standardized to alkamide content.
Findings: Mean global severity scores trended toward benefit for echinacea (236 vs 264 for placebo) but did NOT reach statistical significance (P = 0.089). Mean illness duration approximately 7 hours shorter with echinacea (not significant). Authors concluded no clinically significant effect.
Limitations: Study may have been underpowered for the effect size actually observed. Used dried root extract (different from fresh aerial part preparations with positive results). Combined two Echinacea species. Does not exclude possibility of modest benefit.
[13]
Echinacea for URI in children (negative trial with safety signal)
RCT of 407 children aged 2-11 years (707 URI episodes analyzed). Used dried whole-plant E. purpurea preparation.
Findings: No difference in URI duration (median 9 days in both groups) or severity. Increased incidence of rash in the echinacea group compared to placebo. E. purpurea was NOT effective in this pediatric population.
Limitations: Used dried whole plant (not a standardized preparation). Doses may have been insufficient for body weight. Rash finding raises safety concern for pediatric use. Results cannot be generalized to other preparations or age groups.
[14]
Preparations & Dosage
Fresh Juice / Expressed Juice
Strength: Expressed juice of fresh aerial parts, preserved with 22% ethanol
Freshly expressed juice from aerial parts (Presssaft). Preserved with ethanol (typically 22% v/v alcohol as preservative). This is the pharmaceutical form used in the Commission E positive monograph and many European clinical trials.
6-9 mL daily in divided doses
Divided into 2-3 doses per day
Maximum 10 days for acute treatment. Consult healthcare provider if symptoms persist beyond 10 days.
Not recommended under age 12 (EMA). Health Canada: ages 2-4: proportionally reduced; ages 5-9: proportionally reduced; ages 10+: see adult doses
This is the traditional European pharmaceutical form. Products: Echinacin (Madaus), Echinacea-ratiopharm Liquid. Initiate at first signs of symptoms for best results.
Tincture
Strength: Root tincture: 1:5, 45% ethanol (commonly cited). Fresh herb tincture ratios vary by manufacturer.
Hydroethanolic extraction of root or whole plant. Root tincture typically uses 45-55% ethanol. For fresh herb tincture (e.g., Echinaforce), 65% ethanol with 95% herba and 5% root.
Root tincture: 1-4 mL three times daily. For acute infections, some protocols recommend 3 mL every 3-4 hours for first 1-2 days, then 3 mL three times daily for subsequent week.
Three times daily (maintenance); every 3-4 hours (acute, first 1-2 days)
Maximum 10 days acute treatment. For prevention, limited duration recommended; consult practitioner for use beyond 8 weeks.
Not recommended under age 12 (EMA)
Fresh herb tinctures and ethanolic extracts appeared to show superior clinical results to pressed juices in Schapowal 2015 meta-analysis. Alkamides are more effectively extracted by ethanol; polysaccharides by aqueous extraction.
Decoction
Strength: 1-2 teaspoons dried root per 240 mL water
Simmer 1-2 teaspoons (approximately 2-4 g) of dried root per cup of water for 15-20 minutes. Strain and allow to cool slightly before drinking.
6-8 oz (180-240 mL) up to 3 times daily. Some protocols: 4 times daily for first 2 days of acute symptoms, then reduce to 1-2 times daily for days 3-7.
1-3 times daily (routine); up to 4 times daily (acute, first 2 days)
Up to 10 days for acute use
Not well-established. Consult practitioner.
Decoction extracts primarily polysaccharides and water-soluble caffeic acid derivatives. Alkamides are poorly extracted in water. Aqueous preparations may have a different mechanism of action profile than ethanolic preparations.
[4]
Capsule / Powder
Strength: Varies widely by product. Standardization may target alkamide content and/or cichoric acid content.
Dried powdered root or herb in capsule form. Quality varies significantly between products.
Dried herb: 2.5-6.0 g daily in divided doses. Dried root: 0.9-4.5 g daily in divided doses.
Divided into 2-3 doses per day
Maximum 10 days acute treatment. Consult practitioner for use beyond 8 weeks.
Health Canada: ages 2-4: dried herb 0.4-1.0 g/day, dried root 0.15-0.8 g/day. Ages 5-9: dried herb 0.6-1.5 g/day, dried root 0.23-1.1 g/day.
Barrett 2010 trial used dried root capsules (E. purpurea + E. angustifolia, standardized to alkamide content) and found only a non-significant trend toward benefit. Dried preparations may lose significant active compound content during processing and storage.
Standardized Extract
Strength: EMA radix: DER 5.5-7.5:1 (extraction solvent ethanol or water). Echinilin: 0.25 mg/mL alkamides, 2.5 mg/mL cichoric acid, 25 mg/mL polysaccharides. Echinaforce: 95% herba, 5% root, ethanolic extract.
Standardized liquid or dry extract with defined levels of marker compounds. Quality-controlled preparations.
Product-specific. Echinilin (Goel 2004): standardized to 0.25 mg/mL alkamides, 2.5 mg/mL cichoric acid, 25 mg/mL polysaccharides. Echinaforce tablets: 2400 mg/day (Jawad 2012). EMA radix dry extract DER 5.5-7.5:1.
Per product label; typically 3 times daily
Maximum 10 days acute treatment. Prevention use up to 4 months demonstrated safe in Jawad 2012 trial.
Not established for most standardized products
Standardized extracts showed the most consistent positive results in clinical trials. Standardization targets vary between manufacturers (alkamides, cichoric acid, polysaccharides, or combinations).
Poultice
Dried or fresh root mashed and applied directly to affected area, or powdered root mixed with water to form paste. Cover with clean cloth.
Apply to affected area as needed
Replace 2-3 times daily
Consult healthcare provider if wound does not improve within 1 week (EMA guideline)
Traditional Native American wound-care application. Root poultice historically applied to wounds, swellings, sores, and snakebites. Commission E approved for external use on poorly healing superficial wounds.
Safety & Interactions
Class 1
Can be safely consumed when used appropriately (AHPA Botanical Safety Handbook)
Contraindications
Allergic reactions including urticaria, angioedema, bronchospasm, and anaphylaxis have been reported, particularly in atopic individuals. Patients with allergies to ragweed, chrysanthemums, marigolds, daisies, or other Asteraceae plants are at increased risk.
Commission E listed this as a contraindication based on theoretical concern that immunostimulation could exacerbate these conditions. This is INCREASINGLY QUESTIONED by modern researchers. Lipophilic Echinacea preparations containing alkamides may actually suppress (not stimulate) certain overactive immune responses. No clinical evidence confirms harm in autoimmune patients. Several review articles have called for re-evaluation of this contraindication. Neri et al. 2015 (PMID 26441065): long-term studies up to 6 months showed no toxicological concerns.
EMA: not recommended for children under 12. Taylor 2003 trial (PMID 14657066) found no efficacy and increased rash incidence in children aged 2-11. Some products (e.g., Canadian-approved) have pediatric dosing for ages 2+ under practitioner guidance.
Drug Interactions
| Drug / Class | Severity | Mechanism |
|---|---|---|
| Immunosuppressants (cyclosporine, tacrolimus, sirolimus, corticosteroids) (Immunosuppressants) | theoretical | Echinacea's immunostimulatory activity may theoretically counteract the immunosuppressive effects of these drugs. |
| CYP3A4 substrates (e.g., itraconazole, fexofenadine, lovastatin) (CYP3A4 substrates) | minor | Some in vitro evidence of CYP3A4 inhibition, but in vivo pharmacokinetic studies with standardized E. purpurea preparations showed NO clinically significant inhibition of CYP2D6 or CYP3A4. |
| CYP1A2 substrates (e.g., caffeine, theophylline) (CYP1A2 substrates) | minor | Some evidence of CYP1A2 modulation in vitro. |
Pregnancy & Lactation
Pregnancy
insufficient data
Lactation
insufficient data
EMA: not recommended during pregnancy and lactation due to insufficient safety data (precautionary principle). However, some observational studies and expert opinion suggest oral echinacea is possibly safe during the first trimester at typical dosages for up to 7 days. A prospective cohort study (Gallo et al. 2000) of 206 women using echinacea during first trimester found no increased risk of major malformations. Long-term traditional use supports a reasonable safety profile, but definitive data are lacking. Advise consulting healthcare provider.
Adverse Effects
References
Monograph Sources
- [1] German Commission E (Bundesinstitut fur Arzneimittel und Medizinprodukte). Commission E Monograph: Echinacea purpurea herba (Purple Coneflower Herb) -- Positive. Bundesanzeiger (Federal Gazette) (1992)
- [2] Committee on Herbal Medicinal Products (HMPC), European Medicines Agency. European Union Herbal Monograph on Echinacea purpurea (L.) Moench, herba recens. European Medicines Agency (2017)
- [3] Committee on Herbal Medicinal Products (HMPC), European Medicines Agency. European Union Herbal Monograph on Echinacea purpurea (L.) Moench, radix -- Revision 1. European Medicines Agency (2017)
- [4] World Health Organization. WHO Monographs on Selected Medicinal Plants, Volume 1: Radix Echinaceae. World Health Organization, Geneva (1999) : 136-144
- [5] National Center for Complementary and Integrative Health (NCCIH). Echinacea: Usefulness and Safety. NCCIH, National Institutes of Health (2023)
- [6] Health Canada, Natural and Non-prescription Health Products Directorate. Echinacea purpurea Monograph. Health Canada NHPID (2018)
Clinical Studies
- [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 : 473-480 . DOI: 10.1016/S1473-3099(07)70160-3 . PMID: 17597571
- [8] Jawad M, Schoop R, Suter A, Klein P, Eccles R. Safety and efficacy profile of Echinacea purpurea to prevent common cold episodes: a randomized, double-blind, placebo-controlled trial. Evid Based Complement Alternat Med (2012) ; 2012 : 841315 . DOI: 10.1155/2012/841315 . PMID: 23024696
- [9] 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 . DOI: 10.1002/14651858.CD000530.pub3 . PMID: 24554461
- [10] Goel V, Lovlin R, Barton R, Lyon MR, Bauer R, Lee TDG, Basu TK. Efficacy of a standardized echinacea preparation (Echinilin) for the treatment of the common cold: a randomized, double-blind, placebo-controlled trial. J Clin Pharm Ther (2004) ; 29 : 75-83 . DOI: 10.1111/j.1365-2710.2003.00542.x . PMID: 14748902
- [11] Schulten B, Bulitta M, Ballering-Bruhl B, Koster U, Schafer M. Efficacy of Echinacea purpurea in patients with a common cold: a placebo-controlled, randomised, double-blind clinical trial. Arzneimittelforschung (2001) ; 51 : 563-568 . DOI: 10.1055/s-0031-1300080 . PMID: 11505787
- [12] 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 : 187-200 . DOI: 10.1007/s12325-015-0194-4 . PMID: 25784510
- [13] Barrett B, Brown R, Rakel D, Mundt M, Bone K, Barlow S, Ewers T. Echinacea for treating the common cold: a randomized trial. Ann Intern Med (2010) ; 153 : 769-777 . DOI: 10.7326/0003-4819-153-12-201012210-00003 . PMID: 21173411
- [14] Taylor JA, Weber W, Standish L, Quinn H, Goesling J, McGann M, Calabrese C. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA (2003) ; 290 : 2824-2830 . DOI: 10.1001/jama.290.21.2824 . PMID: 14657066
Traditional Texts
- [15] Felter HW, Lloyd JU. King's American Dispensatory (18th edition, 3rd revision). Ohio Valley Company, Cincinnati (1898)
- [16] Lloyd JU. A Treatise on Echinacea. Lloyd Brothers, Cincinnati (1917)
- [17] Hobbs C. Echinacea: From Native American Panacea to Modern Phytopharmaceutical. HerbalGram (1994)
- [18] Kindscher K. The Uses of Echinacea angustifolia and Other Echinacea Species by Native Americans. Springer International Publishing (2016) . DOI: 10.1007/978-3-319-18156-1_2
Pharmacopeias & Reviews
- [19] Manayi A, Vazirian M, Saeidnia S. Echinacea purpurea: Pharmacology, phytochemistry and analysis methods. Pharmacogn Rev (2015) ; 9 : 63-72 . DOI: 10.4103/0973-7847.156353 . PMID: 26392710
- [20] Burlou-Nagy C, Banita F, Octavian G, Radu N, Hegedus I, Cernea S. Echinacea purpurea (L.) Moench: Biological and Pharmacological Properties. A Review. Plants (2022) ; 11 : 1244 . DOI: 10.3390/plants11091244 . PMID: 35567252
- [21] Pellati F, Benvenuti S, Magro L, Melegari M, Soragni F. Analysis of phenolic compounds and radical scavenging activity of Echinacea spp.. J Pharm Biomed Anal (2006) . PMID: 16302756
- [22] Kraus GA, Bae J, Wu L, Wurtele E. Patterns of Variation in Alkamides and Cichoric Acid in Roots and Aboveground Parts of Echinacea purpurea (L.) Moench. Plant Physiol (2006) . PMID: 16299170
Last updated: 2026-02-26 | Status: review