raíz de grava

Gravel Root (Eupatorium purpureum / Eutrochium purpureum)

1. Identity, Botanical Classification, and Common Names

Gravel root is a perennial herbaceous plant whose medicinal use centres on its root and rhizome. In older herb books it appears under the name Eupatorium purpureum; in modern botany it is often placed in the genus Eutrochium. Joe-Pye weeds were initially included in the genus Eupatorium, but as early as the 19th century Franco-American botanist Constantine Samuel Rafinesque proposed separating them into their own genus Eutrochium. The tall purple-flowered Joe-Pye weeds have been changed twice recently — from Eupatorium to Eupatoriadelphus and now seem settled into the genus Eutrochium. The accepted current binomial is therefore Eutrochium purpureum (L.) E. E. Lamont, with Eupatorium purpureum L. retained as the longstanding synonym most commonly encountered in the herbal, pharmacological, and clinical literature.

The full accepted name in current taxonomy is Eutrochium purpureum (Linnaeus) E. E. Lamont, with common names including sweet Joe-Pye weed, green-stemmed Joe-Pye weed, queen of the meadow, gravel root, kidney root, and purple boneset. Additional synonyms encountered in commerce and older literature include Eupatoire Pourpre, Eupatoriadelphus purpureus, Herbe de Joe Pye, Kidney Root, Purple Boneset, Queen of the Meadow, Roter Wasserhanf, and Trumpet Weed.

The plant belongs to the family Asteraceae (the daisy family). The common name "Gravel Root" refers to the herb's administration in kidney stones (gravel). The genus name Eutrochium, proposed by Rafinesque in 1838, derives from the Greek words eu (well or true) and trochos (wheel), alluding to the distinctive whorled leaf arrangement that resembles a wheel.

1.1 Morphology and Natural Habitat

Gravel root is a perennial herbaceous plant native to North America. It is native to North America, from Ontario east to New Hampshire and south as far as Florida, Louisiana, and Oklahoma. Eupatorium purpureum is a perennial growing to 2 m (6 ft) by 1 m (3 ft 3 in) at a fast rate. These plants typically grow 30–350+ cm tall with erect, often purple-tinged stems that bear whorled leaves (3–7 per node) and terminal corymbiform arrays of discoid flower heads containing 4–22 purplish to pinkish florets, which bloom from July to September and attract pollinators such as butterflies and bees.

It is a clump-forming plant with erect stems and whorls of finely toothed lance-shaped leaves to 25 cm long, vanilla-scented when crushed. It belongs to the Asteraceae family and is native to eastern North America, where it grows in damp meadows, woodland edges, and streamside areas. The root should be harvested in autumn, after the plant has finished flowering, then washed, sliced, and dried.

1.2 Parts Used and Common Preparations

Parts used are the rhizome and root. In practical terms, when people purchase gravel root as an herbal product, they are usually looking for dried root, powdered root, tincture, or a formula aimed at urinary support. The most common consumption methods of gravel root today are in the forms of teas, tinctures, and capsules.

2. Traditional and Historical Use

2.1 Nomenclature and Legendary Origins

According to folklore, the name Eupatorium is derived from King Mithridates Eupator, among the first to use the herb medicinally. This refers to King Mithridates VI of Pontus, also known as Eupator Dionysius, who lived circa 120–63 BC.

The common name honors Joe Pye, a 19th-century New England herbalist who reportedly used the plants to treat fevers. The term "jopi" was used by Native Americans to describe typhoid fever, a disease often treated by gravel root. As the colonists learned of the plant's use and name, it likely became pronounced and spelled as "Joe Pye" weed.

2.2 Native American Use

Gravel root has a long tradition of use by Native American tribes, including the Cherokee and Iroquois, who used it to treat urinary tract infections, kidney stones, and fevers. A mainstay herb of the early Native American Iroquois, Cherokee, and Ojibwe tribes, the gravel root was known as "little medicine water."

The Abenaki tribe used gravel root as a mild diaphoretic to induce perspiration and break a fever. The Cherokee nation used gravel root in the treatment of joint disorders and, due to its diuretic, soothing, and astringent effect, also in urinary tract problems. It was often made into a decoction or cold infusion and given for urinary gravel, back pain from kidney issues, and water retention. Native American Indians thought of it as an antilithic (kidney-stone-dissolving) agent and traditionally used it for softening and dissolving kidney stones and promoting the passage of debris in the kidney.

2.3 Eclectic Medicine (19th–Early 20th Century)

In the 19th-century Eclectic medical tradition, gravel root was regarded as one of the most important herbs for renal and reproductive system health, especially for cases of urinary irritation, cystitis, and stone formation. The Eclectic physicians — a school of US doctor-herbalists from about 1830 to 1910 — mention E. purpureum in their materia medica. A specimen of Eupatorium purpureum is preserved in the Smithsonian Institution as part of materia medica representing plants introduced and employed by physicians of the Eclectic School.

The common name "gravel root" indicates the traditional use of the drug, and in the hands of Eclectics it did good work in cases of irritable bladder, diabetes insipidus, incontinence of urine, and calculous affections. Eclectic practitioners also mentioned that impotency had been treated in the male, and sterility and uterine atony in the female.

2.4 Traditional Preparations and Purposes Across Cultures

Gravel root was used by Native Americans as a diaphoretic to induce perspiration and break a fever. The plant was quickly adopted by white settlers and still finds a use in modern herbalism. The whole plant, but especially the root, is astringent, diuretic, nervine, and tonic.

It works particularly on the genito-urinary system and the uterus. Especially valued as a diuretic and stimulant, as well as an astringent tonic, a tea made from the roots and leaves has been used to eliminate stones from the urinary tract, treat urinary incontinence in children, cystitis, and urethritis.

According to the British Herbal Pharmacopoeia (1983) and Wren (1988), the herb has traditionally been used to treat urinary stones, cystitis, dysuria, urethritis, prostatitis, rheumatism, and gout, especially renal or vesicular stones.

Traditionally, gravel root was used in a similar way to its relative Boneset (Eupatorium perfoliatum) for fevers and as a tonic for debility, especially in older people.

3. Key Chemical Constituents and Active Compounds

Constituents include volatile oil (0.07%), flavonoids (euparin), resin (eupurpurin), iron phosphate, potassium chloride, silica, calcium, sodium, acid phosphate, and pyrrolizidine alkaloids.

Further phytochemical analysis of the crude extract led to the isolation of three known benzofurans — euparin, euparone, and 6-hydroxy-3β-methoxytrematone — and a new benzofuran: 5-acetyl-6-hydroxy-2-(1-oxo-2-acetoxy-ethyl)-benzofuran.

The most pharmacologically studied constituent is cistifolin. The active principle of gravel root has been isolated and identified as 5-acetyl-6-hydroxy-2,3-dihydro-cis-2-isopropenyl-3-tiglinoyloxybenzofuran. Chemical constituents also include benzofurans, euparin, cistifolin, and euparone.

The root and rhizome contain active compounds such as euparin (a volatile oil), flavonoids, sesquiterpene lactones, and alkaloids, which contribute to its traditional role as a diuretic, anti-inflammatory, and urinary tract tonic.

Benzofurans and dihydrobenzofurans have been found in a number of Eupatoriinae and are particularly well represented in E. cannabinum, with coumarins scattered across the investigated genera members.

4. Established Mechanisms of Action

4.1 Anti-inflammatory Activity via Integrin Inhibition

The most extensively documented mechanism of gravel root involves the compound cistifolin and its effects on integrin-mediated cellular adhesion. Previous research revealed that cistifolin from the antirheumatic herbal drug gravel root showed activity in both in vitro and in vivo models of inflammation. In addition to LFA-1 and other integrin-mediated leucocyte adhesions, cistifolin inhibits the Mac-1 (CD11b/CD18)-dependent monocyte adhesion to fibrinogen in a concentration-dependent manner.

During routine screening of medicinal plants for small molecular-weight inhibitors of cell adhesion, the crude ethanolic extract of the antirheumatic herbal drug gravel root was identified as a potent inhibitor of some beta-1 and beta-2 integrin-mediated cell adhesions. Cistifolin inhibited integrin-dependent cell–cell and cell–protein interactions in vitro with EC50 values between 7–20 micrograms/ml.

As with indomethacin, cistifolin administered orally two hours before induction of inflammation (in rat paw) by carrageenan inhibited oedema formation in a dose (10 and 50 mg/kg)-dependent manner. This is an animal (in vivo, rodent) study; no equivalent human clinical data for this mechanism currently exists.

None of the isolated benzofuran compounds — euparin, euparone, and the hydroxymethoxy derivative — were active in suppressing integrin-mediated monocytic U937 cell adhesions in vitro. Biological activity in the inflammation model therefore appears attributable primarily to cistifolin rather than to the co-occurring benzofurans.

4.2 Diuretic Activity

As a diuretic, gravel root is considered to stimulate the flow of water and solutes. According to the literature, the plant is anti-lytic, diuretic, anti-inflammatory, and antirheumatic. The specific molecular mechanisms underlying the diuretic action of gravel root have not been elucidated in controlled clinical or preclinical studies as of current literature.

4.3 Antilithic (Stone-Dissolving) Properties

Gravel root is classified in traditional practice as an antilithic agent. Medicinal actions attributed to it include use as a diuretic, renal stone solvent, stimulating nervine, tonic, and alterative, with primary medicinal uses in the treatment of renal and urinary calculi. The mechanism by which it may affect stone formation or dissolution has not been elucidated in controlled human studies. The main underlying mechanisms proposed for dietary plants in the management of urolithiasis include diuretic, antispasmodic, and antioxidant activity, as well as inhibitory effects on crystallization, nucleation, and aggregation of crystals. Whether gravel root operates through any of these specific pathways has not been demonstrated in verified clinical research.

5. Scientific Evidence by Area of Use

5.1 Urinary Tract Conditions, Urolithiasis, and Kidney Stones

Despite safety concerns, people use gravel root for conditions such as bladder infections, kidney stones, arthritis pain, and fever, but there is no good scientific evidence to support these uses. Gravel root might work for certain conditions by reducing swelling (inflammation).

Despite this traditional use, the only real evidence surrounding gravel root's power for reducing kidney stones is anecdotal.

Broader reviews of phytotherapy in urolithiasis do not specifically highlight gravel root as a well-supported agent. A 2025 narrative review published in the Journal of Clinical Medicine (PMC12072574) assessed phytotherapy in urolithiasis, noting that use of herbal medicines in urolithiasis is on the rise and is mainly utilized as complementary therapy to conventional treatment, but several questions regarding specific dosages, mechanisms of action, drug interactions, treatment duration, and types of stones that respond to phytotherapy remain unanswered. Gravel root is not identified within that review as having sufficient human evidence to recommend it specifically for nephrolithiasis.

There are no robust modern human trials showing that gravel root reliably prevents kidney stones, treats urinary tract infections, relieves prostatitis, or improves arthritis in a clinically meaningful way. Broader reviews of plant-based support for urolithiasis and urinary complaints do not elevate gravel root to the level of a well-proven front-line therapy. The evidence can be summarized as: traditional use — strong and longstanding; mechanistic plausibility — present; human clinical evidence — limited.

Evidence strength: Traditional and anecdotal only; no published controlled human trials specifically on gravel root for urolithiasis or urinary tract infection have been identified in the peer-reviewed literature.

5.2 Anti-Inflammatory and Antirheumatic Effects

The anti-inflammatory activity of the antirheumatic herb Eupatorium purpureum has been demonstrated in both in vitro and in vivo models of inflammation. The primary investigator in this field, S. Habtemariam, published a series of studies in the late 1990s and 2001.

The 1998 study in Planta Medica identified cistifolin and characterized its mechanism: during screening of medicinal plants, the crude ethanolic extract of gravel root was identified as a potent inhibitor of beta-1 and beta-2 integrin-mediated cell adhesions; the active principle cistifolin was isolated and identified, inhibited integrin-dependent interactions in vitro with EC50 values of 7–20 μg/ml, and when administered orally inhibited carrageenan-induced rat paw oedema in a dose-dependent manner at 10 and 50 mg/kg.

The 2001 study in Phytotherapy Research (Habtemariam 2001) further confirmed that cistifolin inhibits Mac-1 (CD11b/CD18)-dependent monocyte adhesion to fibrinogen in a concentration-dependent manner. The crude ethanol extract of E. purpureum was further investigated for its anti-inflammatory activity; cistifolin and four benzofurans were isolated and subjected to bioassay-guided fractionation using in vitro monocyte-endothelial and monocyte-fibronectin adhesion bioassays. Only cistifolin showed strong activity, supporting its potential use for treatment of inflammation.

However, clinical trials are limited and most evidence relies on traditional use. The quality of available evidence is generally low due to the lack of rigorous clinical studies.

Evidence strength: In vitro and animal (rodent) studies only. No published randomized controlled trials or other clinical human studies are available for the antirheumatic or anti-inflammatory indications.

5.3 Gout

The diuretic properties of gravel root make it helpful (in the traditional and herbalist view) in osteoarthritis and gout, drawing out impurities by increasing the flow of urine. It is also said to be helpful in treating rheumatism and gout by increasing the removal of waste from the kidneys. No human clinical trial data specific to gout have been identified.

Evidence strength: Traditional and theoretical only; no controlled human evidence.

5.4 Fever and Diaphoretic Use

Folk use among some Native American tribes of Eastern North America employed gravel root to cure fevers and typhoid. People also use gravel root for arthritis-like pain (rheumatism) and gout, as well as for fever from malaria, dengue virus, or typhus. No modern clinical evidence supports these applications; they remain categorized as historical or traditional use only.

Evidence strength: Historical and folk use only; no clinical human data.

5.5 Prostatitis and Pelvic Health

Due to its diuretic properties, gravel root has been used for urinary infections and urinary gravel. It has been used to good effect along with herbal analgesics and anti-inflammatories in cases of prostatitis. Gravel root is indicated (in traditional herbal practice) for irritable bladders, enlarged prostates, and kidney diseases related to high uric acid. No controlled clinical trials for prostatitis have been identified.

Evidence strength: Traditional/clinical herbalism only; no controlled human trial data.

6. Body Systems and Health Areas Associated with Gravel Root

• Urinary/Renal System: Gravel root is primarily known for its historical and ongoing use in urinary system support, especially for conditions involving gravel-like sediment or small kidney stones. It has been used to help flush the kidneys and bladder, reduce inflammation in the urinary tract, and relieve painful or difficult urination.
• Musculoskeletal System: It can be of help in gout and "rheumatism" — a catch-all term used to describe conditions characterized by pain and stiffness in the muscles, joints, or surrounding fibrous tissue.
• Reproductive/Pelvic System: It works particularly on the genito-urinary system and the uterus.
• Immune/Inflammatory Response: Pharmacological activity includes anti-inflammatory and antirheumatic action.
• Integumentary/Lymphatic (diaphoretic): Gravel root was used by Native Americans as a diaphoretic to induce perspiration and break a fever.
• Fluid/Electrolyte Regulation: It is also valued for promoting fluid movement, which can help with edema, gout, and rheumatism by encouraging uric acid elimination.

7. Dosage Forms and Reported Dosages

The following dosages are reported in herbal reference sources; they are not derived from controlled clinical trials and should be understood as traditional or practitioner-reported figures only:

• Tincture (fresh root, 1:4; 35% alcohol): 1–5 ml three times daily. Dried root tincture (1:5; 25% alcohol): 1–5 ml three times daily.
• Decoction: 1 teaspoon per cup, 1 to 2 cups per day.
• A decoction at the strength of 1 teaspoon in a cup of water, simmered for 10 minutes, is recommended three times daily. In tincture form, 1–2 ml three times daily is recommended.
• Decoction: 2 teaspoons per cup of water; or 1:1 fresh strength liquid extract: 10–40 drops 1–4 times per day.

Standardized dosing for gravel root is weak. No dosage has been established through rigorous human clinical trials.

8. Safety Considerations and Notable Interactions

8.1 Pyrrolizidine Alkaloids and Hepatotoxicity

The central and most significant safety concern with gravel root is the presence of pyrrolizidine alkaloids (PAs). There is a lot of concern about using gravel root as medicine, because it contains chemicals called hepatotoxic pyrrolizidine alkaloids (PAs). These chemicals may block blood flow in the veins and cause liver or lung damage.

Gravel root preparations that are not certified and labeled "hepatotoxic PA-free" are considered likely unsafe. There is not enough reliable information to know if it is safe to take "hepatotoxic PA-free" gravel root by mouth.

Several Eupatorium species, such as Eupatorium cannabinum (hemp agrimony) and Eupatorium purpureum (gravel root), have hepatotoxic potential due to the presence of pyrrolizidine alkaloids.

The liver changes pyrrolizidines into potent alkylating agents that react rapidly with cell constituents resulting in cellular destruction or abnormal cell growth patterns. Accumulation of this cellular damage is known as hepato-veno-occlusive disease (HVOD).

Hepatotoxic PAs might also cause cancer and birth defects.

Because of the pyrrolizidine alkaloids, internal use, particularly long-term use, may lead to hepatotoxicity and should be avoided in patients with liver disease.

8.2 Uncertainty About PA Content in Gravel Root Specifically

It is possible, but certainly by no means definite, that gravel root may contain hepatotoxic pyrrolizidine alkaloids. Adulteration of gravel root with other family members such as Boneset (Eupatorium perfoliatum) can be a risk, along with the common occurrence of interspecies hybridization, which has the potential to cause an alteration in the plant's phytochemical profile. Overall, the research is contradictory and contamination issues are a likely possible issue.

This is not a casual everyday herb. Modern human research is thin, product quality can vary, and there are meaningful safety questions around possible pyrrolizidine alkaloid exposure and adulteration with related plants.

8.3 Topical and Skin Application

It is likely unsafe to apply gravel root to broken skin. The dangerous chemicals in gravel root can be absorbed quickly through broken skin and can lead to dangerous body-wide toxicity.

8.4 Pregnancy and Lactation

The use of gravel root is contraindicated in pregnancy due to its abortifacient effect and during breast-feeding, again due to the pyrrolizidine alkaloids. It is likely unsafe to use gravel root preparations that might contain hepatotoxic PAs during pregnancy.

8.5 Regulatory Context

The American Herbal Products Association (AHPA) recommended in 1996 that all products with botanical ingredients containing toxic pyrrolizidine alkaloids bear the following cautionary statement on the label: "For external use only."

8.6 Adulteration and Species Confusion

It is important to ensure one is obtaining an authenticated source of this plant. There can be hybridization with other species or adulteration and contamination with other related species such as Boneset (Eupatorium perfoliatum).

9. Evidence Summary

Many of the bioactive compounds responsible for gravel root's attributed benefits are beginning to be analyzed by the scientific community in order to validate the age-old claims. While solid, modern evidence to confirm the assertion of kidney stone dissolution is sparse, the root itself exhibits a host of compounds that have earned it attention among naturopaths and herbalists.

The overall evidence landscape for gravel root can be characterized as follows: the traditional record of use is extensive, spanning multiple Indigenous North American traditions and the Eclectic medical tradition of the 19th to early 20th century. Phytochemical research, especially the series of studies by Habtemariam published between 1998 and 2001, has identified a plausible anti-inflammatory mechanism via cistifolin's inhibition of integrin-dependent cell adhesion, supported by animal in vivo data. However, despite safety concerns, people use gravel root for conditions such as bladder infections, kidney stones, arthritis pain, and fever, but there is no good scientific evidence to support these uses. No published randomized controlled trials or Phase II/III human clinical studies on any indication for gravel root have been identified. The phytotherapy urolithiasis literature, while growing, does not identify gravel root as among the better-evidenced botanical agents in that category. The primary safety concern — pyrrolizidine alkaloid hepatotoxicity — remains a substantive and unresolved issue affecting suitability for therapeutic use.

References

• Habtemariam S. Cistifolin, an integrin-dependent cell adhesion blocker from the anti-rheumatic herbal drug, gravel root (rhizome of Eupatorium purpureum). Planta Med. 1998;64(8):683–5. PubMed.
• Habtemariam S. Antiinflammatory activity of the antirheumatic herbal drug, gravel root (Eupatorium purpureum): further biological activities and constituents. Phytother Res. 2001;15(8):687–690. Wiley Online Library.
• Phytotherapy in Urolithiasis: An Updated Overview of Current Knowledge. J Clin Med. 2025; PMC12072574. PubMed Central.
• Dietary Plants for the Prevention and Management of Kidney Stones: Preclinical and Clinical Evidence and Molecular Mechanisms. PMC5877626. PubMed Central.
• Gravel Root: Overview, Uses, Side Effects, Precautions, Interactions, Dosing and Reviews. WebMD/Natural Medicines.
• Gravel Root: Health Benefits, Side Effects, Uses, Dose & Precautions. RxList.
• Gravel root (Eutrochium purpureum): Benefits, Safety, Uses. Herbal Reality.
• Eupatorium purpureum (Gravel Root). The Naturopathic Herbalist.
• Eupatorium purpureum — Gravel Root. Plants For A Future (PFAF) Plant Database.
• Eutrochium. Wikipedia.
• The Eupatorium/Eutrochium Story Pt 1. Northeast School of Botanical Medicine (7Song).
• The Eupatorium/Eutrochium Story Pt 2. Northeast School of Botanical Medicine (7Song).
• Eupatorium Purpureum — Queen of the Meadow. King's American Dispensatory. Henriette's Herbal Homepage.
• Eupatorium cannabinum — an overview (including E. purpureum PA data). ScienceDirect Topics.
• Eupatorium purpureum specimen. National Museum of American History, Smithsonian Institution.
• Gravel Root for Urinary Health, Kidney Stones, Safety, and How to Use It. VitaLibrary.
• Gravel root (Eupatorium purpureum). Carahealth Herbal Monograph.
• Antiinflammatory activity of the antirheumatic herbal drug, gravel root — ResearchGate abstract page.
• Integrative Metabolomics and Proteomics Detected Hepatotoxicity in Mice Associated with Alkaloids from Eupatorium fortunei Turcz. PMC9698670. PubMed Central.