Echinacea purpurea

Echinacea purpurea: A Comprehensive Reference

1. Identity and Botanical Description

Botanical and Chemical Names

Echinacea purpurea (L.) Moench is a perennial herbaceous flowering plant, commonly known as purple coneflower, and it belongs to the Asteraceae family. The species name purpurea refers to the purple color of its ray flowers. The genus name Echinacea is derived from the Greek word echinos, meaning hedgehog or sea urchin, an allusion to its spiny central cone. Linnaeus, the Swedish botanist and physician, gave the first "modern" generic name to any species of purple coneflower, Rudbeckia purpurea (1753), after Olof Rudbeck and son, fellow botanists and physicians. The plant is also known as Eastern purple coneflower, Black Sampson, Red Sunflower, Comb Flower, Missouri Snakeroot, and Indian Head.

Natural Source and Habitat

E. purpurea is native to eastern North America and is present in the United States and Canada. This herb grows in rocky, open woods, thickets, and prairies, especially near waterways. Echinacea species are herbaceous, drought-tolerant perennial plants growing up to 140 cm (4 ft 7 in) in height; unlike most of its relatives, E. purpurea grows from a short caudex with fibrous roots rather than a taproot.

The Echinacea genus is originally from North America, and its species are widely distributed throughout the United States. There are nine different species of Echinacea, but only three of them are used as medicinal plants with wide therapeutic uses: Echinacea purpurea (L.) Moench, Echinacea pallida (Nutt.) Nutt., and Echinacea angustifolia DC.

Commercial Status and Plant Parts Used

E. purpurea is now the primary species of commerce because it is cultivated more easily than its relatives. After only three years, roots of cultivated E. purpurea can be harvested at 1,200 pounds per acre. Historically wild-harvested, it now is cultivated widely outside its native range for the international natural products market. It is typically sold as a dietary supplement component in the United States and as an herbal drug for use in medicinal products in other countries.

2. Traditional and Historical Use

Native American Use

Echinacea has been used as a medicinal herb in North America for more than 400 years. Echinacea has long been used as a traditional medicine. Echinacea angustifolia was widely used by the North American Indigenous peoples as folk medicine, with archaeological evidence dating back to the 18th century. Traditional use included external application (insect bites, burns, wounds), chewing of roots (throat and tooth infections), and internal use (cough, pain, snake bites, and stomach cramps). Some Plains tribes used Echinacea for cold symptoms.

Traditional use of E. purpurea by Native Americans is documented for only three groups: the Delaware, Choctaw, and Yuchi. An elder of the Delaware tribe reported that E. purpurea was used medicinally and called "horse-hobble weed." Native American Plains Indians relied on echinacea as an all-purpose antiseptic. The Sioux tribe valued the root as a remedy for snakebite, the Cheyenne tribe chewed the root to quench thirst, and another tribe washed their hands in a decoction of echinacea to increase their tolerance of heat.

Archaeological digs have found evidence of echinacea use by the Lakota Sioux dating back to the 17th century. The Sioux were said to use it to treat syphilis. Other tribes known to have used echinacea include the Choctaw, Pawnee, and Cheyenne.

Historically, echinacea was regarded as an "anti-infective" agent, commonly used to address bacterial and viral infections, mild septicemia, furunculosis, and a range of skin conditions, such as boils, carbuncles, and abscesses. It was also traditionally employed in the treatment of nasopharyngeal catarrh, periodontitis, and tonsillitis, as well as a supportive remedy for flu-like symptoms, recurring respiratory tract infections, and urinary tract infections. Externally, it was applied to poorly healing superficial wounds.

Adoption by European-American Medicine

In the mid-1800s the American Eclectic physicians began to use echinacea and its use spread to Europe, where it gained even more popularity. By the beginning of the 20th century, it was one of the most frequently used herbal medicines in the United States, which eventually led to the widespread overharvesting of this wild perennial. Along with Echinacea pallida and Echinacea angustifolia, it was the most widely used plant drug in the US in the 19th century.

The herb fell out of popular use in the United States with the availability of antibiotics. The first commercial European preparation of echinacea was made over 50 years ago by Gerhard Madaus under the name Echinacin.

Regulatory and Pharmacopeial History

Although Echinacea root was an official drug monographed in the National Formulary of the United States from the fourth edition (NF IV, 1916) until its omission from the ninth edition (NF IX, 1950), the official compendial history of E. purpurea did not begin until the late 20th century. In March 1989, the Commission E of the German Federal Health Agency (BGA) published a labeling standard monograph for authorized medicines containing preparations of the fresh pressed juice of the flowering aerial parts of E. purpurea.

A quality standard monograph for E. purpurea root entered the 26th revision of the USP (USP 26) in 2003, and another for E. purpurea aerial parts entered the 29th revision (USP 29) in 2006. Monographs were also developed for processed forms such as powder and dry extract, as well as for the dosage forms of capsules and tablets. In 2006, quality standard monographs for both "Purple Coneflower Herb" (Echinaceae purpureae herba) and "Purple Coneflower Root" (Echinaceae purpureae radix) entered the sixth supplement to the fifth edition of the European Pharmacopoeia (PhEur 5.6). These monographs served as the basis for quality specifications of E. purpurea starting materials to be prepared as active ingredients of herbal medicinal products for marketing in the European Union.

In Germany, where herbs are regulated by the government, the above-ground parts of Echinacea purpurea are approved to treat colds, upper respiratory tract infections, urinary tract infections, and slow-healing wounds.

3. Key Constituents and Active Compounds

Primary Phytochemical Classes

Several significant groups of bioactive compounds with pharmacological activities have been isolated from Echinacea species. The most important components of Echinacea purpurea (L.) Moench are alkylamides, polysaccharides, glycoproteins, flavonoids, and phenolic compounds, which include derivatives of caffeic acid, such as caffeic acid, chicoric acid, caftaric acid, chlorogenic acid, and echinacoside, whose amounts vary based on the plant's sections.

In addition to these components, phylloxanthobilins, β-phellandrene, acetaldehyde, dimethyl sulfide, camphene, hexanal, α-pinene, and limonene are present in all plant tissues regardless of species. Fatty acids, aldehydes, and terpenoids are constituents whose presence depends on the parts of plants used.

Caffeic Acid Derivatives

Among caffeic acid derivatives, several components — caftaric acid, chlorogenic acid, caffeic acid, echinacoside, and cichoric acid — are identified from echinacea extracts. Cichoric acid is the major phenolic compound in E. purpurea, but is only a minor constituent in E. angustifolia and E. pallida. Echinacoside is the main phenolic compound in E. angustifolia and E. pallida, but is found only in trace amounts in E. purpurea.

The main immunostimulatory components of Echinacea extracts were found to be lipophilic alkylamides as well as cichoric acid, which is a derivative of caffeic acid. Cichoric acid (2,3-O-dicaffeoyltartaric acid) was first isolated from Echinacea purpurea and found to cause significant stimulation of phagocytotic activity in an in vitro granulocyte bioassay.

Alkylamides (N-Alkylamides)

Unsaturated N-alkylamide lipids are the main constituent of E. purpurea and E. angustifolia preparations capable of activating the cannabinoid receptor type-2 (CB2), and have been suggested to play a role as potential anti-inflammatory and immune-modulatory principles.

Alkamides from Echinacea have cannabinomimetic properties at both the cannabinoid CB1 and CB2 receptors, reflecting their structural similarity to the endogenous ligand anandamide. The CB1 and CB2 receptors are heptahelical G-protein-coupled receptors with different distributions: CB1 receptors are highly expressed in the central nervous system, while CB2 receptor expression is high in the immune system.

Polysaccharides

From the medium of Echinacea purpurea cell cultures, three homogeneous polysaccharides have been isolated: two neutral fucogalactoxyloglucans with mean molecular weights of 10,000 and 25,000, and an acidic arabinogalactan with a mean molecular weight of 75,000. The fucogalactoxyloglucan of mean molecular weight 25,000 enhances phagocytosis in vitro and in vivo. The arabinogalactan specifically stimulates macrophages to excrete tumor necrosis factor (TNF).

The polysaccharide fraction (molecular weight 5,000–50,000) can stimulate phagocytosis by macrophages and the proliferation of T lymphocytes, improving immune activity.

Phylloxanthobilins

Phylloxanthobilins are also important constituents isolated from extracts of Echinacea purpurea leaves. The breakdown of chlorophyll produces these natural tetrapyrrole compounds. Phylloxanthobilins were identified in the leaves of deciduous trees about 10 years ago and are currently considered a compound class with great bioactivity potential that has yet to be fully studied. There have been no previous reports of phylloxanthobilins being found in sections of a medicinal plant utilized in pharmaceutical formulations.

4. Established Mechanisms of Action

Immunomodulation via CB2 Receptor

Analysis of the standardized tincture Echinaforce™ found that it induced de novo synthesis of tumor necrosis factor α (TNF-α) mRNA in primary human monocytes/macrophages, but not TNF-α protein. LPS-stimulated TNF-α protein was potently inhibited in the early phase but prolonged in the late phase. A study of the main constituents showed that the alkylamides dodeca-2E,4E,8Z,10E/Z-tetraenoic acid isobutylamides and related trienoic and dienoic acid derivatives are responsible for this effect. The upregulation of TNF-α mRNA was found to be mediated by CB2 receptors, increased cAMP, p38/MAPK and JNK signaling, as well as NF-κB and ATF-2/CREB-1 activation. This study was the first to report a possible molecular mechanism of action of Echinacea, highlighting the role of alkylamides as potent immunomodulators and potential ligands for CB2 receptors.

The alkylamides dodeca-2E,4E,8Z,10Z-tetraenoic acid isobutylamide (A1) and dodeca-2E,4E-dienoic acid isobutylamide (A2) bind to the CB2 receptor more strongly than the endogenous cannabinoids. The Ki values of A1 and A2 were determined to be approximately CB2 ~60 nM and CB1 >1,500 nM. Molecular modeling suggests that alkylamides bind in the solvent-accessible cavity in CB2, directed by hydrogen bonding and π–π interactions.

Macrophage Activation and Cytokine Induction

Among the many pharmacological properties reported, macrophage activation has been demonstrated most convincingly. Phagocytotic indices and macrophage-derived cytokine concentrations have been shown to be Echinacea-responsive in a variety of assays. Activation of polymorphonuclear leukocytes and natural killer cells has also been reasonably demonstrated. Changes in the numbers and activities of T- and B-cell leukocytes have been reported, but are less certain. Despite this cellular evidence of immunostimulation, pathways leading to enhanced resistance to infectious disease have not been adequately described.

Macrophages cultured in concentrations of echinacea as low as 0.012 μg/ml produced significantly higher levels of IL-1, TNF-α, IL-6, and IL-10 (P < 0.05) than unstimulated cells. The high levels of IL-1, TNF-α, and IL-10 induced by very low levels of echinacea are consistent with an immune-activated antiviral effect.

Synergistic Effects of N-Alkylamide Combinations

Ethanolic E. purpurea radix and herba extracts produce synergistic pharmacological effects on the endocannabinoid system in vitro. Superadditive action of N-alkylamide combinations was seen at the level of intracellular calcium release as a function of CB2 receptor activation. Synergism of the radix and herba tinctures was observed in experiments measuring LPS-stimulated cytokine expression from human PBMCs. While the expression of the anti-inflammatory cytokine IL-10 was significantly superstimulated, the expression of the pro-inflammatory TNF-α was modulated.

N-alkylamides have been shown to reach nanomolar plasma concentrations in humans despite their relatively moderate bioavailability, and depending on the initial dose, potentially bioactive concentrations can be reached. There is good evidence that the major bioavailable Echinacea N-alkylamides in part mimic the action of endocannabinoids.

Alkylamide Effects on Macrophage Function

Among the components isolated from E. purpurea, alkylamides at the dose level of 12 μg/kg body weight/day significantly increased the phagocytic activity as well as the phagocytic index of alveolar macrophages in an in vivo rat model.

5. Common Forms and Preparations

E. purpurea is available in teas, creams, lotions, tablets, capsules, and other forms. Dietary supplement preparations of echinacea are primarily based on extracts or juices from their roots, leaves, stems, and flowers.

The Canadian Natural Health Products Directorate (NNHPD) monograph includes the flowering tops in dried or juice form, as well as the dried root and/or dried root and herb tops prepared in non-standardized dosage forms, specifically dry extract, fluidextract or tincture, herbal tea decoction or infusion, or powder.

Key preparations recognized in official monographs and the literature include:

• Expressed juice (Succus): The fresh-pressed aerial parts (herb) are the basis for several approved European preparations and were the basis for the German Commission E monograph approval.
• Tincture: An alcohol-based liquid extract, commonly prepared at 1:5 ratios in ethanol.
• Dry extract / standardized extract: Concentrated powdered forms encapsulated in tablets or capsules.
• Herbal tea: Prepared by infusion or decoction of aerial parts or roots.
• Topical preparations: Creams, gels, and ointments applied to skin lesions and slow-healing wounds.

Different products use different parts of the echinacea plant, which is why the effectiveness of echinacea may differ from one product to another.

6. Scientific Evidence by Area of Use

6.1 Upper Respiratory Tract Infections and the Common Cold

This is by far the most extensively studied indication for E. purpurea. The weight of evidence from systematic reviews and meta-analyses is mixed.

Cochrane Review (2014): A 2014 Cochrane review of 24 double-blind randomized controlled trials involving 4,631 participants concluded that echinacea products have not been shown to provide benefits for treating colds. Although there is the potential that some preparations are more effective than placebo for treating colds, the overall evidence for clinically relevant treatment effects is weak. This same review also concluded that the results of individual prophylaxis trials consistently show positive (though not significant) trends, although potential effects are of questionable clinical relevance.

2013 Review (E. purpurea-specific): A 2013 review concluded that therapeutic use of Echinacea purpurea may improve cold symptoms in adults, but the evidence is inconsistent. The review also concluded that prophylactic use of echinacea preparations is ineffective for preventing the common cold.

Meta-analysis (DARE-assessed): A review of randomized trials found that treatment with echinacea significantly reduced cold incidence and duration compared with placebo. The review had some potential limitations, including the possibility of missed studies and possible bias in the study selection process.

Jawad et al. (2012) — Largest Single RCT: 755 healthy subjects were allocated to receive either an alcohol extract from freshly harvested E. purpurea (95% herba and 5% root) or placebo. Participants recorded adverse events and rated cold-related issues in a diary throughout the investigation period; nasal secretions were sampled at acute colds and screened for viruses. Echinacea reduced the total number of cold episodes, cumulated episode days within the group, and painkiller-medicated episodes. Echinacea inhibited virally confirmed colds and especially prevented enveloped virus infections (P < 0.05). Echinacea showed maximal effects on recurrent infections, and preventive effects increased with therapy compliance. Compliant prophylactic intake of E. purpurea over a 4-month period appeared to provide a positive risk-to-benefit ratio.

Bräunig et al. (1992) — Dose-response trial: A double-blind, placebo-controlled trial examined the effectiveness of an ethanolic extract made from the root of E. purpurea (1:5, 55% ethanol) in relieving symptoms and duration of flu-like infections in 180 volunteers. Subjects were divided into three groups of 60 and administered echinacea at 450 mg/dose, 900 mg/dose, or placebo. Those who received only 450 mg/dose showed improvement only comparable to the placebo. Those receiving 900 mg/dose showed a statistically significant improvement. An effect from the higher dose was seen after three to four days, but the full effect was not seen for 8 to 10 days.

Yale and Liu (2004) — Negative finding: In a randomized, double-blind, placebo-controlled trial, researchers sought to determine the efficacy of a standardized preparation of E. purpurea in reducing symptom severity and duration of the common cold. Patients received either 100 mg of E. purpurea (freeze-dried pressed juice from the aerial portion of the plant) or a lactose placebo 3 times daily until cold symptoms were relieved or until the end of 14 days, whichever came first. While some studies concluded that Echinacea effectively reduces the symptoms and duration of the common cold, this group was unable to replicate such findings. Further studies using different preparations and dosages of E. purpurea were recommended to validate previous claims.

AAFP Assessment: Based on the current literature, it appears that prophylactic echinacea does not have a significant impact on the frequency, severity, or duration of upper respiratory infection. The data regarding treatment of upper respiratory infection appear to support a modest positive effect.

Evidence summary: Overall, evidence for E. purpurea in the prevention of the common cold is weak and inconsistent across large systematic reviews. For treatment, there is a possible modest benefit, particularly for adult symptom reduction, but results differ substantially by preparation, dose, plant part, and population studied. The 2014 Cochrane review remains the most comprehensive synthesis and characterizes the overall evidence as weak for clinically relevant effects.

6.2 Immune System Modulation

Key bioactive compounds — alkamides, caffeic acid derivatives, flavonoids, and polysaccharides — contribute to immunomodulatory effects. These compounds enhance immune cell activity, including macrophages and natural killer cells, stimulating cytokine production and phagocytosis.

A series of experiments demonstrated that E. purpurea extracts demonstrate significant immunomodulatory activities. Among the many pharmacological properties reported, macrophage activation has been demonstrated most convincingly. Phagocytotic indices and macrophage-derived cytokine concentrations have been shown to be Echinacea-responsive in a variety of assays. Activation of polymorphonuclear leukocytes and natural killer cells has also been reasonably demonstrated.

E. purpurea crude polysaccharides at 100 μg can significantly stimulate macrophages to kill P815 tumor cells, improve the macrophage production of interleukin level of endothelin 1 (IL-1), and stimulate the proliferation of B lymphocytes in mice. All of these results have indicated that E. purpurea crude polysaccharides can enhance humoral immune function.

Evidence strength: The mechanistic (in vitro and animal) evidence for immunomodulatory activity is considerable and relatively consistent across multiple independent laboratories. However, as NCCIH notes, recent NCCIH-sponsored research suggests that the activity of echinacea extracts is influenced by soil conditions that affect the plant's bacterial community, an important confounding variable that complicates comparisons across studies. Translation to robust clinical outcomes in humans remains incomplete.

6.3 Wound Healing and Dermatological Use

Research has explored the metabolic profiling and molecular wound-healing mechanisms of Echinacea purpurea flowers in aqueous and ethanol extracts in an excision wound-healing model. EP-treated wounds healed faster in this animal model. Cichoric acid may ameliorate inflammation induced by lipopolysaccharides (LPS) in both cell culture and mice models, as well as ameliorate UVA irradiation-induced dermal fibroblast senescence by inhibiting matrix metalloproteinase-3 activity, opening the possibility of beneficial effects of cichoric acid on aging. Caftaric acid may act as an antioxidant, anti-inflammatory, antimutagenic, and anticarcinogenic agent, adding to the potential benefit on the skin. A small dermatological study also showed that E. purpurea preparations may effectively improve hydration of the skin and decrease skin wrinkling without inducing skin irritation.

Evidence strength: Evidence for wound healing is preliminary, consisting mainly of animal experiments and in vitro studies. The small dermatological study on skin hydration and wrinkling is consistent with traditional use but requires larger, methodologically rigorous trials.

6.4 Urinary Tract Infections

Echinacea contributes primarily through its immunomodulatory effects, potentially supporting host defense in urinary tract infections. In Germany, the above-ground parts of Echinacea purpurea are approved to treat urinary tract infections.

Evidence strength: The approval for UTI treatment by the German Commission E reflects traditional use and preliminary evidence. Controlled clinical trial evidence specifically for echinacea in UTIs is limited, and the mechanism is thought to be immunomodulatory rather than direct antimicrobial action.

6.5 Anti-inflammatory Effects

Among its active constituents, alkamides, caffeic derivatives, and polysaccharides seem to contribute to the immune modulator, antiviral, antioxidant, and anti-inflammatory activities of the plant. The chemical components responsible for the immunomodulatory activities of purple coneflower roots are glycoproteins, alkylamides, and polysaccharides.

Evidence strength: Anti-inflammatory effects are well-documented in in vitro and animal models. Direct human clinical trial evidence for anti-inflammatory outcomes as an independent endpoint (outside of respiratory infections) is limited.

7. Body Systems and Health Areas of Association

• Immune system: Modulation of macrophage, natural killer cell, neutrophil, and lymphocyte activity; cytokine production (IL-1, IL-6, IL-10, TNF-α).
• Respiratory system: Prevention and supportive treatment of upper respiratory tract infections, colds, and flu-like illness.
• Integumentary system: Traditional and monograph-based use in poorly-healing wounds, burns, boils, and minor skin lesions; some evidence for skin hydration.
• Urinary system: Commission E and German regulatory approval for supportive use in urinary tract infections.
• Endocannabinoid system: Alkylamides act as partial ligands and modulators at CB2 receptors, placing E. purpurea uniquely among botanical immunomodulators.

8. Dosage Forms and Dosages Reported in Studies

Recommended dosages of echinacea differ widely depending on the product. The most commonly used preparation in the United States is a liquid extract of E. purpurea root; typical dosing of such a preparation would be 3 mL every three to four hours for the first one to two days of upper respiratory illness, then three times daily for the subsequent week.

The European Medicines Agency (EMA) herbal monograph on Echinacea purpurea herba recens specifies a daily dose of 6–9 mL expressed juice. The preparation is noted not to be used for more than 1 week.

Key dosages reported in clinical trials include:

• Bräunig et al. (1992): An ethanolic extract of E. purpurea root (1:5, 55% ethanol) at 450 mg/dose (3× daily) was not superior to placebo, while 900 mg/dose (3× daily) produced statistically significant improvement over placebo in 180 volunteers.
• Yale and Liu (2004): 100 mg of E. purpurea (freeze-dried pressed juice from the aerial portion) 3 times daily until cold symptoms resolved or for up to 14 days.
• Jawad et al. (2012): An alcohol extract from freshly harvested E. purpurea (95% herba and 5% root) over a 4-month period in 755 healthy subjects.
• Egyptian Herbal Monograph (adults, expressed juice): Adolescents, adults, and elderly: 1.5–4.5 mL per dose; daily dose 6–9 mL.
• Egyptian Herbal Monograph (adults, dry extract): Adolescents and adults: 112.5 mg three times daily (daily dose 337.5 mg). Children 6–12 years: single dose 112.5 mg twice daily (daily dose 225 mg).

In echinacea supplements, the active ingredients in recommended amounts depend upon the quality of plant material, preparation procedures, formulations, and storage conditions.

9. Safety Considerations and Drug Interactions

General Tolerability

It is likely safe for most adults to consume products with extracts of E. purpurea, and some mixtures of E. purpurea and E. angustifolia, for short periods of time. Most adverse effects are mild and transitory; they include dizziness, fatigue, headache, and gastrointestinal symptoms. The most common side effects of echinacea are digestive tract symptoms, such as abdominal pain, nausea, or stomach pain.

Adverse events reported during clinical trials following administration of Echinacea mono-preparations were generally mild and mostly without causality.

Allergic Reactions

Some people have allergic reactions to echinacea, which may be severe. Allergic reactions are possible in patients with allergies to ragweed, chrysanthemum, marigold, daisies, or related allergens, given the shared Asteraceae family membership. In a 2003 randomized controlled trial conducted in children, use of Echinacea purpurea was associated with an increased risk of rash. Some children participating in a clinical trial of echinacea developed rashes, which may have been caused by an allergic reaction. There is concern that allergic reactions could be severe in some children.

Autoimmune Conditions and Immunosuppressed Patients

Echinacea should be avoided in patients with autoimmune disorders, multiple sclerosis, advanced HIV infection, tuberculosis, and organ transplants because it may stimulate T cells.

Contraindications to the use of echinacea are controversial. The German Commission E monograph recommends that echinacea not be used in patients with autoimmune conditions or HIV infection, because of the risk that its immunostimulating effect could lead to exacerbation of autoimmune illness or increase in HIV viral load; however, this risk is theoretic and has not been adequately studied.

However, some research has challenged this blanket contraindication: The contraindications in cases of autoimmune diseases and immune suppression are questionable, since lipophilic Echinacea preparations containing alkamides suppress cellular immune responses, and beneficial effects in autoimmunity have been reported.

Long-Term Use

Due to published long-term studies with continuous ingestion of different Echinacea preparations for up to 6 months with no reported toxicological concerns, Echinacea can be recommended also for long-term use, according to one pharmacological safety assessment. The safety profile in the large Jawad et al. trial over 4 months was consistent with this, finding that the safety of Echinacea was noninferior to placebo.

Drug Interactions and Cytochrome P450

Echinacea inhibits some cytochrome P-450 enzymes and induces some enzymes; it can therefore potentially interact with medications metabolized by these pathways. In pharmacokinetic herb-drug interaction studies performed in vivo, no significant inhibitions of human CYP2D6 and CYP3A4 isoforms have been found after the administration of standardized E. purpurea preparations. However, contradictory results exist in studies using liver microsomes.

Echinaforce was found to be unlikely to affect CYP3A4 transcriptional levels, even at concentrations which can inhibit the enzymatic activity of CYP3A4. This data provides further evidence for the lack of interactions between Echinacea and conventional drugs.

Current evidence indicates that the risk of drug interactions between Echinacea supplements and most medications is low, according to the National Center for Complementary and Integrative Health (NCCIH).

Children

It is possibly safe for children to consume E. purpurea extract for short periods of time. The effects of echinacea in children are uncertain; only a small amount of research has been done in children, and the results of that research are inconsistent.

Regulatory Status

Regulatory authorities have not approved Echinacea products for any medical use under drug approval pathways in the United States. In contrast, preparations of the aerial parts of E. purpurea do carry official regulatory approval in Germany and are subject to the EMA herbal monograph framework in the European Union.

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