Eupatorium

Other Names

Ageratina altissimaAgue WeedAgueweedAmerican BonesetBastard AgrimonyBonesetByddon ChwerwCommon BonesetCommon Dutch AgrimonyCommon Hemp AgrimonyDog-fennelEupatoire à feuilles de ChanvreEupatoire ChanvrineEupatoire D'Eau RougeEupatorioEupatorium cannabinumEupatorium chapmaniiEupatorium connatumEupatorium cuneatumEupatorium fistulosumEupatorium fortuneiEupatorium japonicumEupatorium lindleyanumEupatorium perfoliatumEupatorium purpureumEupatorium rugosumEutrochium purpureumFeverwortFortune's Eupatorium HerbGrass RootGravel RootGravel WeedGravelwortHamp-hjortetrøstHampflockelHanf-WasserdostHemp AgrimonyHemp WeedHindhealHjortetrøstHollow Joe-Pye WeedHoly RopeIndian Ague RootIndian Gravel RootIndian SageIndian SanicleJoe Pye WeedJopi WeedKidney RootKidney WortKoninginnenkruidKoyunpitragiPeilanPride of the MeadowPurper LeverkruidPurple BonesetPurple Hemp AgrimonyQueen of the MeadowQueen of the PrairieQuill WortRoter WasserhanfSisters of HealingSkunkweedSpotted Joe-Pye WeedSt. John's HerbSweating PlantSweet Joe-Pye WeedSweet-scented JoepyeweedSweet-smelling TrefoilThoroughwortTrumpet WeedTrumpetweedWasserdostWasserhanfWater AgrimonyWater HempWater MaudlinYemazhui佩兰

Synopsis

Eupatorium: A Comprehensive Reference Article

1. Identity, Taxonomy, and Botanical Classification

1.1 Genus Overview and Taxonomy

Eupatorium is a genus of flowering plants in the family Asteraceae, containing from 36 to 60 species depending on the classification system. Most are herbaceous perennials growing to 0.5–3 m (1.6–9.8 ft) tall; a few are shrubs. The genus is native to temperate regions of the Northern Hemisphere. The genus name itself has deep historical roots: the genus is named for Mithridates Eupator, king of Pontus. More specifically, it comes from King Mithridates VI of Pontus, also known as Eupator Dionysius, who lived circa 120–63 BC, and is linked to the herbal world through a concoction called Mithridate, a poison antidote.

The genus has undergone extensive taxonomic revision over the past century. Eupatorium has at times been held to contain as many as 800 species, but many of these have been moved to other genera, including Ageratina, Chromolaena, Condylidium, Conoclinium, Critonia, Cronquistianthus, Eutrochium, Fleischmannia, Flyriella, Hebeclinium, Koanophyllon, Mikania, and Tamaulipa. The genus has been divided into three main genera: Ageratina, Eutrochium, and a more narrowly defined Eupatorium. The traditionally defined genus Eupatorium has been dismantled into smaller, homogeneous, and monophyletic groups based on morphological and phylogenetic evidence. The circumscription of Eupatorium has been narrowed through phylogenetic analyses and now includes approximately 69 accepted species, primarily in temperate eastern North America, Europe, and eastern Asia, leaving only a limited number in the Neotropics.

Some species, such as Boneset (Eupatorium perfoliatum), have stayed within the genus, while the tall purple-flowered Joe-Pye weeds have been changed from Eupatorium to Eupatoriadelphus and now seem settled into the genus Eutrochium. The common names for the plants are all based on the previous usage of one species, Eupatorium perfoliatum, as an herbal medicine.

1.2 Medically Significant Species

Several species within the broader Eupatorium complex carry the majority of traditional and scientific pharmacological interest. The most frequently discussed in the scientific literature are:

Eupatorium perfoliatum L. (Boneset, Common Boneset, Thoroughwort, Feverwort, Agueweed) — a perennial herb popularly known as "boneset," belonging to the family Asteraceae and considered a native plant of North America. Leaves and flowering parts of the plant are the main herbal material; it is also known as boneset, feverwort, ague weed, Indian sage or thoroughwort.
Eupatorium cannabinum L. (Hemp Agrimony) — a species commonly found in regions such as middle and northern Europe, temperate Asia, and northern America, Hemp-agrimony being one of the well-known species. In Europe, only Eupatorium cannabinum is found natively.
Eupatorium purpureum L. / Eutrochium purpureum (Gravel Root, Joe-Pye Weed, Queen of the Meadow) — now reclassified to Eutrochium purpureum in many systems, but historically and commercially still widely referred to as Eupatorium purpureum. Synonyms include E. falcatum, Eutrochium purpureum, Cunigunda purpurea, and Eupatoriadelphus purpureus; E. maculatum, E. fistulosum, and E. verticillatum are said to have similar properties.
Eupatorium fortunei Turcz. (Pei Lan) — the plant is used medicinally in both Japan and China; in Traditional Chinese Medicine it is indicated for poor appetite, nausea and vomiting due to "dampness" obstructions or summer heat.
Eupatorium lindleyanum DC. (Yemazhui) — also known as "Yemazhui," has been traditionally used to treat coughs, chronic bronchitis, and hypertension for thousands of years in China.

1.3 Botanical Description and Natural Habitat

Eupatorium perfoliatum is a common native to the Eastern United States and Canada, widespread from Nova Scotia to Florida, west as far as Texas, Nebraska, the Dakotas, and Manitoba. It is nearly always found in low, wet areas. It grows up to 100 cm (39 inches) tall, with opposite, serrate leaves that clasp the stems (perfoliate). Eupatorium purpureum is a perennial growing to 2 m (6ft) by 1 m (3ft 3in) at a fast rate. These plants are often found in decorative settings along riverbanks and ditches and have historically been used for various medicinal purposes.

1.4 Parts Used and Common Preparations

Preparations of E. perfoliatum include MeOH-, EtOH-, and DCM (dichloromethane) extracts, alongside several subfractions and isolated polysaccharides, sesquiterpene lactones, and flavonoids, all prepared from the aerial parts of the plant. Traditionally and commercially, preparations include dried aerial parts, alcoholic tinctures, liquid extracts, and infusions/decoctions (hot-water extracts). Hemp agrimony (E. cannabinum) grows in damp woods, ditches, marshes, and open areas, and is gathered when in flower in summer; aerial parts and root are both used. For gravel root (E. purpureum), the root is the primary part used medicinally.

2. Traditional and Historical Use

2.1 Native American and Early North American Use of E. perfoliatum

Eupatorium perfoliatum was used in traditional medicine by Native Americans, who applied extracts for fever and common colds. By the early 20th century, it was reported as commonly used by rural African-Americans in the Deep South to treat fever, including dengue fever. In herbal medicine, the plant is a diaphoretic, or an agent to cause sweating. It was introduced to American colonists by natives who used the plant for breaking fevers by means of heavy sweating, and was commonly used to treat fever by the African-American population of the southern United States.

The name "boneset" comes from the use of the plant to treat dengue fever, which is also called "break-bone fever." The plant was typically prepared as a tea or decoction from the leaves and flowering tops to treat fevers, colds, influenza, and rheumatism. Some tribes used it as a general tonic and immune system booster.

Throughout most of the 1800s and the first half of the 20th century, many Americans employed a practice of medicine known as Eclectic Medicine. Together with traditional medicines, the Eclectic physicians developed and utilized botanical remedies that were native to North America along with some known botanicals from the European tradition. Their motto was to "sustain the vital force," or balance function to support the return to health. Aerial parts of Eupatorium perfoliatum have been traditionally used by American natives as a treatment for fever and infections. Modern phytotherapy in Europe also documents the use of hydroalcoholic extracts of this herbal material for the treatment of infections of the upper respiratory tract.

Extracts from E. perfoliatum have been extensively used by the Native Americans, especially for the treatment of feverish diseases like influenza, common cold, and also for malaria, a widespread disease in North America up to the 19th century.

2.2 European Traditional Use of E. cannabinum

Hemp agrimony (E. cannabinum) was known to Avicenna (980–1037 CE) and other practitioners of Arabian medicine in the early Middle Ages. It has been used for a long time for medicinal purposes due to its various pharmacological effects and richness in active compounds such as phenolics, sesquiterpenes, pyrrolizidine alkaloids, and polysaccharides. The plant has been used in traditional medicine for the treatment of diarrhea and liver diseases. More recently, hemp agrimony has found use as an immunostimulant, helping to maintain resistance to acute viral and other infections.

2.3 Traditional Use of E. purpureum (Gravel Root)

The root of Eupatorium purpureum was traditionally used by native North American peoples as a diaphoretic to promote perspiration and reduce fevers. It has been used in kidney stones, gout, chronic uterine disease, and inflammation. The plant contains benzofurans, euparin, cistifolin, and euparone.

2.4 Traditional Chinese Medicine Uses

Eupatorium fortunei is used medicinally in both Japan and China. In Traditional Chinese Medicine it is indicated for poor appetite, nausea and vomiting due to "dampness" obstructions or summer heat. The traditional Chinese herbal medicine Eupatorium fortunei Turcz. has been widely adopted to treat nausea, diabetes, siriasis, and poor appetite.

Eupatorium lindleyanum DC., also known as "Yemazhui," has been traditionally used to treat coughs, chronic bronchitis, and hypertension for thousands of years in China. It is a traditional Chinese herb known for its phlegm-reducing, cough-relieving, and asthma-calming properties and is widely used for treating cough and bronchitis. It is traditionally recognized for its properties of relieving cough, dispelling phlegm, clearing heat, and detoxifying. Many preparations of E. lindleyanum have been widely used clinically to treat various diseases of the respiratory system.

3. Key Constituents and Active Compounds

3.1 Overview of the Genus

The reported constituents from the genus Eupatorium involve flavonoids, terpenoids, pyrrolizidine alkaloids, phenylpropanoids, quinonoids, essential oils, and others — altogether more than 300 compounds. Among them, flavonoids and terpenes are the two main chemical constituents of Eupatorium.

3.2 Constituents of E. perfoliatum

The phytochemical composition of Eupatorium perfoliatum includes volatile oil, caffeic acid derivatives, flavonoids, sesquiterpene lactones, tannins, and polysaccharides. More specifically, phytochemical investigations have identified:

Sesquiterpene lactones: including eupafolin, euperfolitin, eufoliatorin, euperfolide, eucannabinolide, and helenalin. The search for active compounds has yielded seven sesquiterpene lactones: four structurally similar guaianolides, one dimeric guaianolide, and two germacranolides, from a plant with well-documented use for the treatment of fever, flu, and malaria.
Flavonoids: including quercetin, kaempferol, hyperoside, astragalin, rutin, and eupatorin.
Caffeic acid derivatives: including 3-caffeoylquinic acid (chlorogenic acid), 5-caffeoylglucaric acid, and 3,5-dicaffeoylquinic acid.
Immunoactive polysaccharides: from the alkaline aqueous extract of the herbal part of E. cannabinum and E. perfoliatum, two homogeneous polysaccharides (PI and PII) have been isolated; both, identified as 4-O-methylglucuronoxylans, show a phagocytosis-enhancing effect as determined in three immunological test systems.
Pyrrolizidine alkaloids (PAs): Present in small but toxicologically significant quantities — see Safety section.
Volatile oil, sterols, and diterpenes.

3.3 Constituents of E. cannabinum

Hemp agrimony contains a volatile oil (with alpha-terpinene, p-cymene, thymol, and an azulene), sesquiterpene lactones (especially eupatoriopicrin), flavonoids, pyrrolizidine alkaloids, and polysaccharides. HPLC analysis has revealed the presence of eupatorin, eupatilin, and quercetin in chloroform fractions and caffeic acid and rutin in aqueous fractions. Chemical profiles of E. cannabinum essential oils are described according to the first predominant components: germacrene D (≤22.0%), neryl acetate (≤20.0%), spathulenol (≤27.2%), and α-terpinene (11.5%).

Previous pharmacological studies revealed that E. cannabinum possessed cytotoxic, antimicrobial, antioxidant, anti-inflammatory, immunological, choleretic, hepatoprotective, insecticidal, and repellent effects.

3.4 Constituents of E. lindleyanum

More than 100 compounds have been isolated from E. lindleyanum, including triterpenes, sesquiterpenes, sesquiterpene lactones, flavonoids, acyclic diterpenoids, sterols, and others. Among them, terpenoids are considered to be the most important bioactive substances. More than 100 bioactive ingredients have been identified, including triterpenoids, sesquiterpenes, diterpenoids, organic acids, flavonoids, volatile oils, and amino acids.

4. Mechanisms of Action

4.1 Anti-inflammatory Activity

Hydroalcoholic extracts have been described to exert in vitro potent anti-inflammatory activity related to the sesquiterpene lactones and the flavonoid eupafolin. Additionally, antioxidative effects and strong antiplasmodial effects, due to the sesquiterpene lactone fraction, have been reported. Immunological activity was tested within lymphocyte transformation tests on peripheral blood mononuclear cells (PBMC), and tests on the enhancement of phagocytosis and of nitric oxide (NO) production by murine RAW 264.7 macrophages. Anti-inflammatory effects were assessed from LPS-stimulated RAW 264.7 cells by NO/iNOS quantification, gene array, real-time PCR, and ELISA.

Eupafolin decreased the LPS-induced release of inflammatory mediators (iNOS, COX-2, and NO) and proinflammatory cytokines (IL-6 and TNF-α) from RAW 264.7 macrophages. Eupafolin inhibited the LPS-induced phosphorylation of p38 MAPK, ERK1/2, JNK, AKT, and p65, and the nuclear translocation of p65 and c-fos.

4.2 Immunomodulatory Activity

From water or alkaline-water extracts of Eupatorium cannabinum and Eupatorium perfoliatum, polysaccharide fractions with molecular weights in the range of 25,000 to 500,000 and higher have been isolated, which, according to granulocyte and carbon clearance tests, showed significant immunostimulating activities. The isolated compounds belong to the group of water-soluble, acidic heteroglycanes. The linkages in the different polysaccharides do not represent a uniform structural type.

However, the postulated immunostimulating properties have not been unambiguously established in vitro. It should be reevaluated whether the tested polysaccharides had been LPS-depleted prior to use, because LPS contamination, which occurs regularly during aqueous extraction, will lead to dramatic activation of macrophages. Effects found for the isolated sesquiterpene lactone eufoliatin have to be assessed in a quantitative way to ensure that active and stimulating amounts are indeed present in relevant concentrations in traditionally used extracts. From these in vitro data, direct stimulation activities of E. perfoliatum extracts on the first barrier immune defence have not been approved.

4.3 Antiviral Mechanisms

Hydroalcoholic extracts from the aerial parts of E. perfoliatum and its main active polyphenolic constituents protect cells from influenza A virus (IAV) infection by inhibiting viral attachment to the host cells. The extract was found able to inhibit strongly the virus growth by blocking the viral entry. This activity is possibly due to proanthocyanidin compounds, which showed promising antiviral effects.

4.4 Antiplasmodial Activity

Strong antiplasmodial effects, due to the sesquiterpene lactone fraction, have been reported for E. perfoliatum. This is consistent with the plant's historical use for malaria treatment by Native Americans and 19th-century Eclectic physicians.

4.5 Pharmacological Activities of E. cannabinum

P-cymene found in hemp agrimony is antiviral, while eupatoriopicrin has anti-cancer properties and inhibits cellular growth. The polysaccharides stimulate the immune system. Many species possess a wide range of pharmacological activities, such as cytotoxic, antifungal, insecticidal, antibacterial, anti-inflammatory, and antinociceptive activities.

4.6 Pharmacological Activities of E. lindleyanum

The pharmacological functions of E. lindleyanum, including anti-asthmatic, anti-tussive, anti-inflammatory, anti-hyperlipidemic, anti-hypertensive, antiviral, and anti-tumor activities, have been widely investigated. However, most of the studies are preclinical research.

5. Scientific Evidence by Area of Use

5.1 Infectious Respiratory Disease (Influenza, Common Cold)

This is the area with the most concentrated human study of Eupatorium perfoliatum. Only one clinical investigation describing positive effects of Eupatorium perfoliatum against the common cold is documented — a non-placebo-controlled, open study with n=53 patients with common cold (Gassinger et al., 1981). One group was treated with a homeopathic preparation from Eupatorium perfoliatum (D2, meaning 1:100 dilution titer); the other group was treated with acetyl salicylic acid (3×500 mg/day). The efficacy of the drugs was assessed after 1, 4, and 10 days.

Clinical studies of E. perfoliatum hydroalcoholic extract are related to the investigations of Gassinger et al. (1981) for treatment of common cold. This study did not indicate a positive outcome for the verum-treated group. Furthermore, two non-GCP (Good Clinical Practice) investigations with E. perfoliatum extract have been reported for improvement of symptoms of common cold (Bentley and Grünwald, 2006; Tradler and Eckert, 2001), which indicated positive effects.

Evidence strength: Possible effects of E. perfoliatum for these uses remain undefined by adequate scientific research, and are unconfirmed by high-quality clinical research. The clinical data base is limited to small, methodologically weak studies and non-GCP investigations. No randomized, double-blind, placebo-controlled trials of a sufficient scale have been published.

5.2 Anti-inflammatory Applications

Preclinical studies indicate anti-inflammatory effects of ethanolic extracts of E. perfoliatum, which can be correlated on a molecular level to eupafolin and sesquiterpene lactones. Antiplasmodial, antioxidative, and immunomodulating activities are additionally documented in preclinical work.

In vitro data from LPS-stimulated macrophage models (RAW 264.7) show significant downregulation of pro-inflammatory cytokines. Significant (for IL-1α and IL-1β) and moderate (for TNF-α) downregulation of cytokines after LPS challenge was reported for methanol, ethanol, and dichloromethane extracts.

Evidence strength: All anti-inflammatory evidence is from cell-based (in vitro) and animal models. No human clinical trials specifically investigating the anti-inflammatory effects of Eupatorium in an inflammatory condition have been published. Evidence is preliminary and preclinical only.

5.3 Antiviral Activity

The aim of the antiviral study was to characterize the anti-influenza A virus (IAV) potential of extracts from the aerial parts of E. perfoliatum and to identify their antiviral mode of action. The inhibitory effects of extracts obtained by different organic solvents with different polarities on the cytopathic effect induced by IAV replication were determined in a Madin-Darby Canine Kidney Epithelial (MDCK II) cell-based assay measuring cell viability by MTT stain.

Evidence strength: Antiviral data is from cell culture (in vitro) studies only. While the mechanism (inhibition of viral attachment) is clearly characterized, no human clinical evidence exists specifically for this antiviral mechanism. The extract is described as "a promising expansion" of anti-influenza agents pending further research.

5.4 Immunomodulatory / Immunostimulant Effects

E. perfoliatum originates from North America, where it has been widely used for centuries by native Indians. Extracts are also used in Europe as immunostimulating agents for treatment of fever and cold. While the postulated immunostimulating properties of Eupatorium perfoliatum have not been confirmed by in vitro data, animal studies and in vitro experiments with plant extracts indicate anti-inflammatory effects alongside antiplasmodial activity.

Evidence strength: Laboratory evidence suggests that polysaccharide fractions can stimulate phagocytic activity. However, the methodology of earlier immunostimulant studies has been questioned, and no well-designed human clinical trials confirm these effects.

5.5 Urinary Tract and Renal Health (E. purpureum)

Gravel root (E. purpureum) is used in kidney stones, gout, chronic uterine disease, and inflammation. Species of Eupatorium have been used in folk medicine, for instance to excrete excess uric acid which causes gout.

Evidence strength: The use of gravel root for urinary/renal conditions is based entirely on traditional and ethnobotanical evidence. No clinical trials have been identified in the peer-reviewed literature that evaluate E. purpureum or Eutrochium purpureum in human subjects for kidney stones, gout, or related urinary conditions.

5.6 Respiratory Conditions — E. lindleyanum (Traditional Chinese Medicine)

Eupatorium lindleyanum DC. has a long history of traditional use in China to cure coughs, chronic bronchitis, lobar pneumonia, and hypertension. Many preparations of E. lindleyanum have been widely used clinically to treat various diseases of the respiratory system. More than 100 compounds have been isolated from the herb, including triterpenes, sesquiterpenes, sesquiterpene lactones, flavonoids, acyclic diterpenoids, sterols, and more.

Evidence strength: The pharmacological functions, including anti-asthmatic, anti-tussive, anti-inflammatory, anti-hyperlipidemic, anti-hypertensive, antiviral, and anti-tumor activities, have been widely investigated in preclinical work. However, most of the studies are preclinical research, and further studies are required to examine the underlying mechanisms of action.

5.7 Antiproliferative / Cytotoxic Effects

Laboratory study of E. cannabinum found eupatorin, eupatilin, and quercetin in chloroform fractions; the antiproliferative potential on BT-20, HepG2, Caco-2, and Jurkat cancer cell lines was assessed by MTS test. Studies have shown that Eupatorium and its active principles possess a wide range of pharmacological activities, including cytotoxic activity.

Evidence strength: All cytotoxic and antiproliferative data are from in vitro cell line studies. There is no clinical oncology evidence for any Eupatorium species preparation.

6. Body Systems Associated with Eupatorium

Immune system: The most prominent association, especially for E. perfoliatum, through polysaccharide immunomodulation and antiviral mechanisms.
Respiratory system: Both the North American boneset and the Chinese E. lindleyanum are used for fevers, colds, coughs, bronchitis, and flu-related illness.
Musculoskeletal / rheumatic: Traditional use for rheumatism, gout, and myalgia across multiple species.
Urinary and renal system: Especially E. purpureum (gravel root), used traditionally for kidney stones, urinary tract infections, and gout.
Gastrointestinal system: Traditional use includes dyspepsia, biliousness, constipation, and liver disorders; E. fortunei is used for nausea in TCM.
Hepatic system: Both a traditional hepatoprotective use and a modern toxicological concern due to pyrrolizidine alkaloids.

7. Dosage Forms and Reported Dosages

Dosage data from published studies and pharmacopoeial sources are limited. The following are specifically sourced from the scientific and clinical literature:

Homeopathic preparation (E. perfoliatum D2): In the Gassinger et al. (1981) clinical investigation, one group was treated with a homeopathic preparation from Eupatorium perfoliatum at D2 dilution (meaning 1:100 dilution titer); the comparator group received acetyl salicylic acid (3×500 mg/day).
Hydroalcoholic extract: Used in vitro antiviral studies for characterization; specific human doses are not established in published trials.
Traditional infusion/decoction: Aerial parts were prepared as a tea or decoction from the leaves and flowering tops, though no standardized dose from a pharmacopoeia monograph on E. perfoliatum was identified in current authoritative sources.
Essential oil research (E. cannabinum): Twenty-two hemp agrimony essential oil samples were prepared by hydrodistillation according to the European Pharmacopoeia for compositional analysis, but therapeutic dosing for humans has not been established in published clinical literature.

No standardized therapeutic dosage for any Eupatorium preparation has been established through controlled clinical trials. The absence of such data reflects the overall lack of robust human clinical investigation.

8. Safety Considerations

8.1 Pyrrolizidine Alkaloid Hepatotoxicity

The most serious and well-documented safety concern across the Eupatorium genus is the presence of pyrrolizidine alkaloids (PAs), which are associated with liver toxicity. Several Eupatorium species, such as Eupatorium cannabinum (hemp agrimony) and Eupatorium purpureum (gravel root), have hepatotoxic potential due to the presence of pyrrolizidine alkaloids.

Pro-toxic dehydropyrrolizidine alkaloids are associated with liver disease in humans. The potential for long-term, low-level, or intermittent exposures to cause or contribute to chronically developing diseases is of international concern. Forty-nine samples of Eupatorium perfoliatum were shown to contain dehydropyrrolizidine alkaloids (0.0002–0.07% w/w), the majority dominated by lycopsamine and intermedine, their N-oxides and acetylated derivatives. Alcoholic tinctures and hot water infusions and decoctions had high concentrations of the alkaloids.

Sampling issues, low and high alkaloid chemotypes of Eupatorium perfoliatum, or interspecies hybridization could cause the wide variation in dehydropyrrolizidine alkaloid concentrations or the different profiles observed. Concerns associated with dehydropyrrolizidine alkaloids provide a compelling reason for preclusive caution until further research can better define the toxicity and carcinogenicity of the dehydropyrrolizidine alkaloid content of Eupatorium perfoliatum.

In isolation, the pyrrolizidine alkaloids are toxic to the liver. For E. fortunei, a mouse study found that total alkaloids markedly decreased mouse body and liver weights and increased the contents of AST and ALT. Histopathological assays demonstrated that, after exposition to the alkaloids, the structures of hepatocytes were damaged and fibrosis and apoptosis in hepatocytes were accelerated. Moreover, the alkaloids increased the serum level of inflammatory cytokines and aggravated circulating oxidative stress.

PAs are protoxins produced primarily by 3% of the world's flowering plants, acting as a natural defense system for producer plants against herbivores, while at the same time potentially becoming hepatotoxic in both animals and humans when ingested. The producer plants are predominantly found within Asteraceae (including Senecio, Eupatorium, and other genera of the tribes Senecioneae and Eupatoriae).

Many phytochemical studies reported that E. fortunei contained multiple pyrrolizidine alkaloids (PAs) that were naturally occurring toxic compounds with genotoxic, neurotoxic, and hepatotoxic properties.

8.2 Contact Allergy and Dermatitis

Sesquiterpene lactones in the Asteraceae family, including some present in Eupatorium, are known sensitizers capable of causing allergic contact dermatitis. This is a general consideration for the Asteraceae family, particularly for individuals already sensitized to related plants. The genus Eupatorium belongs to the family Asteraceae and comprises about 60 species; among species, many possess a wide range of pharmacological activities including cytotoxic properties.

8.3 Essential Oil Toxicity

Toxicity tests evaluated that hemp agrimony oils containing predominant amounts of germacrene D and neryl acetate were notably toxic, with LC50 values of 16.3–22.0 μg/mL.

8.4 White Snakeroot — A Critical Misidentification Risk

There is no evidence of pyrrolizidine alkaloids in Eupatorium rugosum (white snakeroot), but this plant also has poisonous properties, which are attributed to an unstable toxin called tremetol. White snakeroot, now reclassified as Ageratina altissima, is historically responsible for "milk sickness" — a fatal poisoning transmitted through dairy products from cows that grazed on the plant. Accurate botanical identification is essential when sourcing any Eupatorium-related material.

8.5 Honey Contamination

Eupatorium spp. have been found to contaminate honey with toxic pyrrolizidine alkaloids as a result of bee foraging. This represents an indirect exposure pathway independent of direct herbal use.

8.6 Pregnancy and Lactation

Based on the presence of hepatotoxic pyrrolizidine alkaloids, use during pregnancy and lactation is contraindicated across multiple species within the Eupatorium complex. This contraindication is consistent with the general precautionary approach to PA-containing plants during pregnancy.

9. Regulatory and Pharmacopoeial Status

In the European Pharmacopoeia, only Agrimonia eupatoria can be used as [a regulated herbal drug under that monograph — note: this refers to a separate plant sharing a partial name]. Hemp agrimony essential oil samples are prepared by hydrodistillation according to the European Pharmacopoeia for compositional research purposes. E. lindleyanum has been recorded in the China Pharmacopoeia (1977), the Jiangsu Provincial Standard of Local Medicinal Materials 1988, and the China National Pharmacopoeia. The German Homeopathic Pharmacopoeia lists E. perfoliatum for homeopathic preparations. The German Homeopathic Pharmacopoeia does not list specific chromatographic methods for the unambiguous identification of Eupatorium perfoliatum.

10. Summary of Evidence Gaps and Research Status

Across the genus, the following characterizes the current state of the evidence:

Studies have shown that Eupatorium and its active principles possess a wide range of pharmacological activities, such as cytotoxic, antifungal, insecticidal, antibacterial, anti-inflammatory, and antinociceptive activities. Currently, effective monomeric compounds or active parts have been screened for pharmacological activities from Eupatorium in vivo and in vitro.
Human clinical trials for any Eupatorium species are scarce. The most investigated species, E. perfoliatum, has only one published clinical study (Gassinger et al., 1981), which was small, not placebo-controlled, and used a homeopathic dilution.
Extracts appear to be promising subjects for additional phytochemical, pharmacological, and clinical research in the hunt for potent anti-inflammatory and immunomodulatory medicinal herbs.
Pyrrolizidine alkaloid content across botanical samples is variable and poorly characterized, creating a toxicological uncertainty that remains unresolved.
The taxonomy of the group continues to evolve, adding complexity to literature interpretation, as older studies may refer to species names that have since been reclassified.

References

Health Conditions

Health conditions that Eupatorium may help support.

No conditions available.

Body Systems

Body systems that Eupatorium may help support.

No body systems available.