Pharmacognosy · Immunomodulator

Echinacea

Echinacea purpurea (L.) Moench — North America's most-used medicinal herb of the 19th century, whose alkylamides, polysaccharides, and caffeic acid derivatives converge on macrophage activation, CB2 receptor modulation, and multivalent antiviral defence.

59 Primary Refs
9 Properties
Root Parts Used
✦ Researched
Last Updated
Primary Source Wikiphyto · NCBI PubMed
Family Asteraceae
Cochrane Reviewed · German Commission E Approved

Biological Overview

Three Echinacea species hold pharmacopoeial status in France: E. angustifolia, E. purpurea, and E. pallida. Their pharmacological activity stems from the synergistic interplay of three compound classes — alkylamides, polysaccharides, and caffeic acid derivatives — whose combined presence appears essential for full immunomodulatory efficacy. Fresh plant preparations are consistently more potent, as alkylamide content is higher in fresh versus dried material.

Key ActivesAlkylamides, Arabinogalactan, Echinacoside, Cichoric Acid
Primary TargetsMacrophages, CB2 Receptor, NF-κB, Cytokine Network
Cochrane Review2014 — modest cold treatment, consistent prevention efficacy
Commission EApproved — E. purpurea aerial parts
Botanical Classification

Taxonomy & Identification

Latin Names
E. purpurea, E. angustifolia, E. pallida
Family
Asteraceae (Compositae)
Common Names
Echinacea, Purple Coneflower, Hedgehog Plant
French Name
Échinacée, Rudbeckia pourpre
Parts Used
Root (or whole plant with root)
Origin
North America — prairies, dry hills, sandbars
Name Origin
Greek echinos — hedgehog (fruiting capitule shape)
Ethnobotany

History & Tradition

Native Americans of the South Dakota plains — particularly the Lakota — used echinacea as their primary wound-healing and infection-fighting plant. Applications ranged from topical poultices for infected wounds to oral administration of freshly chewed root for snake bites and septic conditions. The root was chewed to relieve toothache, and the whole plant was used as an "alexitere" — an antidote to venomous bites.

Echinacea became the most widely used medicinal plant in the United States during the 19th century, adopted by Eclectic physicians who championed plant-based medicine. Its popularity declined sharply with the introduction of antibiotics in the 1940s, before experiencing a major resurgence in the late 20th century driven by German phytomedicine research — particularly through the work of Professor Heinz Schilcher and later the systematic reviews supporting German Commission E approval.

Today echinacea is among the three best-selling herbal supplements globally. The 2014 Cochrane review, covering 24 randomised controlled trials, provided the most rigorous evaluation of the evidence to date — finding consistent prevention benefit and modest treatment effect, with significant variation driven by species and preparation differences.

🏥

19th Century — Most Used US Medicinal Plant

Before antibiotics, echinacea was the frontline botanical treatment for infections across American medicine. Eclectic physicians documented its use in septicaemia, wound infections, and febrile illness — indications now explained by modern immunopharmacology.

Three Medicinal Species

Echinacea purpurea

Commission E Approved

Rich in cichoric acid and caftaric acid. Commission E approves aerial parts. Alkylamides highest in fresh plant. Most studied species in modern RCTs.

Echinacea angustifolia

Narrow-Leaved Coneflower

Echinacoside concentrated in upper root sections. Primary species used by Native Americans. Rich in alkylamides. French Pharmacopoeia: underground parts.

Echinacea pallida

Pale Coneflower

Echinacoside in roots. Anti-inflammatory and wound healing documented for root extract (Speroni et al., 2002). French Pharmacopoeia: underground parts.

Pharmaceutical Forms

Parts Used & Available Forms

Fresh plant preparations are consistently preferred — alkylamides degrade on drying and polysaccharides are insoluble in alcohol, so preparation method critically determines bioactive content.

Pharmacopoeial Material

Root or whole plant with root. Fresh plant preparations are more active — alkylamide content is higher in fresh versus dried preparations. Three species recognised by the French Pharmacopoeia (List A).

Available Forms

  • ▸ Mother tincture — E. angustifolia whole plant
  • ▸ EPS (standardised plant extract) — E. purpurea root
  • ▸ Fluid extract
  • ▸ Fresh plant juice — preferred for polysaccharides
  • ▸ Dry extract (6.5:1 concentration ratio)
  • ▸ Alcohol tincture (1:5, 45% ethanol)

Preparation Note

Fresh plant juice is preferred because polysaccharides are insoluble in alcohol and are thus absent from tincture preparations. Alcohol-based extracts concentrate alkylamides but lose polysaccharide activity. Ideally, choose preparations that preserve both fractions (aqueous-alcoholic extracts at low alcohol percentage).

Clinical Dosimetry

Dosages

Prevention protocols require discontinuous use — 10 to 15 days per month. Continuous use beyond 8 weeks is not recommended and may cause leucopenia.

Context Form Dose Frequency Notes
Prevention Fluid extract 1 g (50 drops) Once daily Discontinuous cycles — 10–15 days/month
Prevention Mother tincture 50 drops Twice daily Discontinuous cycles only
Prevention EPS 5 ml Once daily Discontinuous cycles — 10–15 days/month
Acute — mild E. purpurea fresh juice 2–3 ml or 1–2 ml extract 1–4× daily In water or sublingual
Acute — standard Dry extract (6.5:1) 150–300 mg 3× daily E. purpurea only
Acute — tincture Alcohol tincture (1:5, 45%) 1–5 ml 3× daily Lower polysaccharide content than juice
Phytochemistry

Composition

The synergistic triad of alkylamides, polysaccharides, and caffeic acid derivatives — rather than any single compound — drives echinacea's immunological efficacy. Composition varies significantly by species, plant part, and preparation method.

Principal Active Compounds

Alkylamides (Alkamides)~2%, ~15 identified compounds; lipophilic fraction; highest in fresh plant; CB2 receptor ligands; isobutylamides of polyacetylenic acids; echinacein is principal alkamide; more concentrated fresh than dried [4]
Principal
High-MW Polysaccharides (>10,000 Da)Arabinogalactan, arabinorhamnogalactan, fucogalactoxyloglucane, glucuronoarabinoxylane — macrophage activators; insoluble in alcohol; present only in aqueous/fresh preparations
Immunoactive
Caffeic Acid DerivativesEchinacoside (0.3–1.3%, E. angustifolia/pallida roots); cichoric acid and caftaric acid (E. purpurea); cynarine — antiviral and antioxidant; composition varies with flowering stage [1]
Antiviral
Indolizidine AlkaloidsMinor fraction; pharmacological significance not fully characterised
Minor
Essential OilHumulene (= alpha-caryophyllene) and echinolone — minor fraction; anti-inflammatory sesquiterpenes
Trace

Species-Specific Chemistry

E. purpurea

Cichoric acid + caftaric acid as principal phenolics. Highest alkylamide content of three species. Commission E–approved aerial parts. Most used in modern clinical trials.

E. angustifolia

Echinacoside concentrated in upper root sections. High alkylamide content. Primary species in traditional Native American use. Pharmacopoeia: underground parts.

E. pallida

Echinacoside in roots. Caffeic acid derivatives dominant phenolic fraction. Anti-inflammatory and cicatrisant activity documented. Pharmacopoeia: underground parts.

Synergy Note

The juxtaposition of all three compound classes — alkylamides, polysaccharides, caffeic acid derivatives — appears critical for full efficacy. Single-compound standardisation may undermine the whole-extract activity. [2][3]

Plant Properties — Pharmacodynamics

Immunological and direct antimicrobial activities across multiple biological axes

9 Properties Cochrane Reviewed Commission E Approved
🛡️

Immunomodulatory — Macrophage Activation

Echinacea acts on multiple immune factors simultaneously. Arabinogalactan stimulates macrophage activity [5]; alkylamides specifically stimulate alveolar macrophages [6] and induce macrophage cytotoxicity [7]. Modulates cytokine production [8], activates NF-κB [9], increases phagocytosis of granulocytes and macrophages, and inhibits PGE2 production. [10] Increases white blood cell count, lymphocyte proliferation, IgM production, and induces TNF-α, IL-1, IL-6, IFN-α and IFN-β.

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Antiviral — Multi-Strain Activity

Broad antiviral activity documented against enveloped viruses through multifunctional virucidal mechanisms. [17][18][19][20] Cichoric acid and echinacoside possess independent antiviral activity. [21] Anti-influenza activity confirmed against highly pathogenic H5N1 and H7N7 strains. [22] In vitro virucidal activity against HCoV-229E, MERS-CoV, SARS-CoV-1 and SARS-CoV-2. [23] Inhibits virus-induced pro-inflammatory cytokine secretion (IL-6 and IL-8/CXCL8).

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Antibacterial — Direct Activity

Direct bactericidal activity demonstrated against Streptococcus pyogenes, Haemophilus influenzae, Legionella pneumophila, methicillin-resistant Staphylococcus aureus (MRSA), and Mycobacterium smegmatis, alongside reduction of induced inflammatory responses. [16] The Echinaforce® standardised extract has demonstrated bactericidal and anti-inflammatory dual action against respiratory pathogens.

🌿

Anti-Inflammatory

Echinacea increases arginase activity and exhibits anti-inflammatory properties in macrophage cells consistent with alternative macrophage activation (M2 phenotype shift). [24] Alkylamides inhibit prostaglandin E2 (PGE2) production in RAW264.7 macrophages [39], reduce COX-2-dependent pathways, and modulate cytokine secretion profiles. E. pallida root extract has documented anti-inflammatory activity in vivo. [29]

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CB2 Cannabinoid Receptor Ligand

Alkylamides are a new class of cannabinomimetics — ligands for CB2 cannabinoid receptors, the primary immunoregulatory cannabinoid receptor. [25][26][27] This CB2 activation mediates TNF-α gene expression modulation via multiple signal transduction pathways and explains much of echinacea's immunomodulatory and anti-inflammatory activity through a mechanism unrelated to conventional herbal immunostimulants. Activates the endocannabinoid system in vitro. [43]

💊

Analgesic

Alkylamides from echinacea have demonstrated analgesic and neuropsychological effects. [28] The analgesic mechanism is likely related to CB2 receptor activation — the same pathway responsible for immunomodulation — consistent with the known role of the endocannabinoid system in pain modulation. Echinacein may also contribute through adrenal-mimetic activity increasing stress resistance.

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Wound Healing & Cicatrisant

Echinacea participates in connective tissue restoration by opposing the hydrolysis of hyaluronic acid — the fundamental structural molecule of connective tissue. [29] This hyaluronidase inhibition preserves the integrity of the extracellular matrix and accelerates wound healing. E. pallida root extract has demonstrated anti-inflammatory and cicatrisant activity in a validated in vivo model (Speroni et al., 2002). This property underpins the traditional Native American topical use for infected wounds.

⚡

Adrenal-Mimetic / Adaptogenic

Echinacein — the principal alkylamide — is described as adrenal-mimetic, producing effects similar to those of ginseng extract on the hypothalamic-pituitary-adrenal axis. This activity is associated with increased resistance to physical exertion and enhanced adaptation to stressors. The mechanism parallels the cortisol-mimetic adaptogenic effects described for other immunostimulant plants, though clinical evidence for this specific effect remains limited compared to the immune properties.

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Antioxidant Synergy

A synergistic antioxidant effect is produced by the combination of alkylamides, caffeic acid derivatives, and polysaccharides fractions against in vitro oxidation of human LDL particles. [3] Cichoric acid contributes direct antioxidant activity through caffeic acid moieties. This synergistic protection exceeds that achievable by any individual fraction, illustrating the value of whole-extract preparations over isolated compounds. Antioxidant activity also contributes to the anti-inflammatory phenotype.

Clinical Applications

Clinical Indications

Indications of the whole plant (phytotherapy) and homeopathic applications, translated from primary literature and the Wikiphyto source.

🤧
Respiratory Infections
Primary Clinical Indication · Cochrane Reviewed
  • Prevention of upper respiratory tract infections: consistent evidence from multiple RCTs [30]; 2014 Cochrane review — weak treatment effect but consistent prevention of cold recurrences [32]
  • Common cold treatment: reduces cold symptoms [31]; Lancet meta-analysis (2007) found 58% reduction in incidence and 1.4-day reduction in duration across multiple trials
  • Influenza prophylaxis and adjuvant treatment: anti-influenza activity confirmed including against H5N1 and H7N7 strains [22]
  • COVID-19 — preliminary: in vitro virucidal activity against SARS-CoV-2 [23]; supplementation associated with reduction in IL-6, IL-8, TNF and increase in IL-10 [36]
💪
Immune Stimulation
Prevention & Curative Potentiation
  • Immunostimulant — prevention: bacterial infections, herpes, cystitis, candidiasis, etc. Acts in prevention and potentiates other therapies curatively [33]
  • Immunodeficient mice: polysaccharides improve resistance to systemic Candida albicans and Listeria monocytogenes infections [14]
  • Adjuvant to chemotherapy: polysaccharides from E. purpurea cell cultures used to counteract undesired effects of chemotherapy (pilot study)
  • Non-specific immune stimulation in vivo in rat models (cichoric acid + polysaccharides + alkylamides combination) [15]
🩺
Topical & Wound Healing
Traditional & Evidence-Based
  • Delayed wound healing: local treatment via hyaluronidase inhibition and connective tissue restoration [29]
  • Dermatitis and skin infections: topical application; anti-inflammatory and cicatrisant activity
  • Fresh plant preferred: topical use benefits from fresh plant juice to preserve polysaccharide activity
🔮
Homeopathic Indications
Traditional Use
  • Septicaemia and suppuration with systemic involvement, torpor, deep pain, dehydration
  • Anthrax, furuncles, adenitis, lymphangitis
  • Phlegmons and gangrene — traditional septic complications
Pharmacodynamics

Mode of Action

Echinacea's immunomodulatory activity is complex and multi-pathway — driven by different compound classes acting on distinct but complementary molecular targets.

🎯

Polysaccharide — Innate Immune Activation

High-molecular-weight polysaccharides (particularly arabinogalactan) are the primary drivers of macrophage activation, phagocytosis enhancement, and non-specific immune stimulation. They are water-soluble and insoluble in alcohol — requiring aqueous or fresh plant preparations for full activity. The glucan fraction stimulates phagocytosis; the galactan fraction stimulates macrophage cytokine production (TNF-α, IFN-β2, IL-1). [37]

🔗

Alkylamides — CB2 & NF-κB Modulation

The lipophilic alkylamide fraction modulates macrophage responses [38], inhibits PGE2 production [39][40], participates in immunostimulation [41], and exerts anti-inflammatory effects [42] through CB2 receptor activation. [43] They modulate NF-κB expression in T-lymphocytes [11] and inhibit IL-2 production in Jurkat T cells independently of direct cytotoxic effects. [12] Standardisation remains challenging as individual alkylamide effects are not fully characterised. [13]

🧪

Caffeic Acid Derivatives — Antiviral & Antioxidant

Cichoric acid and echinacoside are the primary antiviral agents in the caffeic acid fraction, acting through multifunctional virucidal mechanisms against enveloped viruses. They inhibit virus-induced pro-inflammatory cytokine secretion (IL-6 and IL-8) and contribute the antioxidant synergy of the whole extract through free radical scavenging. Polyacetylene derivatives — polyacetylenes — are chemotaxonomic markers of Asteraceae and contribute additional biological activity. [21]

⚙️

Suppression of Epithelial Pro-Inflammatory Responses

Beyond direct immune cell stimulation, echinacea suppresses pro-inflammatory responses of epithelial cells to viruses and bacteria — altering secretion profiles of cytokines and chemokines. [37] This dual action — stimulating immune cells while calming hyperinflammatory epithelial responses — may explain the clinical paradox of echinacea being both immunostimulant and anti-inflammatory. The suppression of virus-induced IL-6 and IL-8 is particularly relevant to upper respiratory infections where cytokine-mediated symptoms dominate.

Legal & Regulatory Status

Regulation

French Pharmacopoeia — List A (Three Species)

Underground parts of Echinacea angustifolia; aerial flowering parts and underground parts of Echinacea purpurea; underground parts of Echinacea pallida — all listed on the French Pharmacopoeia List A.

German Commission E — Approved (E. purpurea)

Activity of Echinacea purpurea aerial parts is formally recognised by the German Commission E — the most rigorous herbal medicine regulatory body in Europe. Commission E approval signifies established efficacy and safety evidence meeting pharmaceutical standards.

Health Canada — Natural Health Products Monograph

Health Canada's Natural Health Products Ingredients Database includes a formal echinacea monograph (18/12/2018) recognising its immunomodulatory and respiratory indications. [30]

Clinical Safety

Safety & Precautions

Echinacea is generally well tolerated. Several absolute contraindications apply — particularly autoimmune and progressive systemic diseases. CYP450 interactions are documented for the alkylamide fraction.

⚠️

Adverse Effects

  • Allergic reactions: cross-reactivity risk within Asteraceae family — atopic individuals should use with caution [47]; Australian pharmacovigilance reports adverse reactions including anaphylaxis
  • Hypereosinophilia: reported case associated with echinacea use [48]
  • Leucopenia: reported with long-term continuous use [49] — use in discontinuous cycles only
  • Hepatotoxicity (rare): rare cases of acute cholestatic hepatitis [50] including one case with positive anti-smooth muscle antibodies suggesting autoimmune mechanism [51]
  • Erythema nodosum: one case reported with concurrent loratadine and echinacea use [59]
🚫

Contraindications & Interactions

  • Absolute contraindications: autoimmune diseases; progressive systemic diseases including tuberculosis, leukaemia, collagenoses, multiple sclerosis, AIDS
  • Pregnancy: not teratogenic [46] but most studies recommend caution [44][45] — reduce doses and use discontinuously
  • CYP450 interactions: alkylamides inhibit CYP isoforms 3A4, 1A2, 2C19, 2D9 [53]; no significant CYP2D6 inhibition noted [52]; interactions are in vitro — limited clinical evidence in vivo [13]
  • Corticosteroids: additive immunomodulatory properties — use with caution
  • Immunosuppressants: theoretical alteration of immunosuppressive effect — avoid unless supervised
  • HIV antiretrovirals: no problems noted with darunavir-ritonavir co-administration [57]; no interaction with docetaxel [58]
Clinical Disclaimer: This monograph is for educational and professional reference only. It does not constitute medical advice, diagnosis, or treatment guidance. Echinacea is contraindicated in autoimmune diseases and progressive systemic conditions. Always consult a qualified healthcare provider before initiating any phytotherapeutic regimen.
Common Questions

Frequently Asked Questions

Does echinacea actually work for colds?
The evidence is nuanced. The 2014 Cochrane review of 24 RCTs found a weak and inconsistent effect on treating colds once established, but a consistent and meaningful reduction in cold recurrence when used preventively. A 2007 meta-analysis in Lancet Infectious Diseases found echinacea reduced cold incidence by 58% and duration by 1.4 days across pooled studies. The major caveat is preparation dependency — results vary significantly by species, plant part, and extraction method. Fresh plant preparations preserving both alkylamides and polysaccharides appear most effective. Dry extracts or alcohol tinctures that lose polysaccharide content may underperform.
What is the correct dosage and how long should I take it?
For prevention: fluid extract 1g/day or EPS 5ml/day in discontinuous cycles of 10–15 days per month — continuous use is specifically not recommended and may paradoxically suppress immunity and cause leucopenia. For acute treatment: fresh juice 2–3ml or dry extract 150–300mg three times daily, or alcohol tincture 1–5ml three times daily. The key clinical principle is that prevention protocols require cycling — echinacea should not be taken continuously like a vitamin supplement. Short intensive courses for acute illness are appropriate.
Can echinacea be used for COVID-19?
In vitro studies show virucidal activity of Echinaforce® against HCoV-229E, MERS-CoV, SARS-CoV-1, and SARS-CoV-2. A 2021 systematic review found echinacea supplementation was associated with reductions in pro-inflammatory cytokines IL-6, IL-8, and TNF alongside increased anti-inflammatory IL-10. These are biologically plausible mechanisms relevant to COVID-19 immunopathology. However, as of 2024, there are no completed large-scale clinical trials establishing echinacea as a proven COVID-19 prevention or treatment strategy. The in vitro and mechanistic data are promising but insufficient for clinical recommendations beyond standard preventive measures.
Who should not take echinacea?
Echinacea is contraindicated in autoimmune diseases (lupus, rheumatoid arthritis, multiple sclerosis), progressive systemic diseases (tuberculosis, leukaemia, collagenoses, AIDS), and in people with known allergy to the Asteraceae plant family (ragweed, chrysanthemum, marigold, daisy — cross-reactivity risk). People who are atopic should use with caution. Pregnancy: echinacea is not teratogenic but most guidelines recommend reduced doses used discontinuously. Immunosuppressed transplant patients should avoid without specialist supervision due to theoretical immune activation opposing immunosuppressive therapy.
Is fresh or dried echinacea better?
Fresh plant preparations are consistently superior in the clinical literature. Alkylamides — the CB2 receptor-active immunomodulatory compounds — are more concentrated in fresh plant extracts than dried. More critically, the high-molecular-weight polysaccharides (arabinogalactan, etc.) are insoluble in alcohol and are completely absent from alcohol tinctures. Since both compound classes contribute complementary and synergistic immunological effects, preparations that preserve both fractions — fresh plant juice or low-alcohol aqueous-alcoholic extracts — are pharmacologically more complete than dried extracts or standard alcohol tinctures.
Does echinacea interact with medications?
The alkylamide fraction inhibits several CYP450 cytochrome isoforms (3A4, 1A2, 2C19, 2D9) in vitro, which could theoretically increase plasma levels of drugs metabolised by these enzymes. However, clinical in vivo evidence for significant drug interactions is limited — no significant CYP2D6 inhibition has been confirmed in human studies, and co-administration with darunavir-ritonavir (HIV) and docetaxel (chemotherapy) has not shown clinically significant problems. The main pharmacodynamic interactions of concern are additive effects with corticosteroids and antagonism of immunosuppressant drugs. As always, disclose echinacea use to your prescriber if you take any regular medication.
Primary Literature

Bibliography

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