Western Herbalism Properties

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Botanical Description

Clematis hexapetala is an erect, perennial herb of the Ranunculaceae, growing roughly 30 to 100 cm tall from a short woody rootstock bearing dense clusters of slender, cord-like roots. Unlike its scrambling relatives, this species is largely non-climbing. The opposite leaves are pinnately or bipinnately divided into narrow, leathery, linear to lance-shaped leaflets with entire margins and prominent parallel veins. The flowers are borne in terminal and axillary cymes and lack true petals; instead they display six (occasionally five to eight) spreading, petaloid sepals that are white and densely silky-hairy on the outer surface, surrounding numerous yellow stamens. Flowering occurs in summer. The fruit is a head of flattened achenes, each tipped with a long, feathery, persistent plumose style that aids wind dispersal. Native to northern China, Mongolia, and the Russian Far East, it grows on dry grassy slopes, steppe, and open scrub.

Native Region: Amur, Buryatiya, China North-Central, China South-Central, China Southeast, Chita, Inner Mongolia, Irkutsk, Khabarovsk, Korea, Manchuria, Mongolia, Primorye

Active Constituents

Oleanolic acid

Pentacyclic oleanane-type triterpenoid

Concentration: The pharmacopoeial assay compound for the drug this species supplies. The Chinese Pharmacopoeia requires Clematidis Radix et Rhizoma to contain not less than 0.30% oleanolic acid, calculated on the dried basis.

The single number a buyer can hold this drug to. It is a widely distributed plant triterpenoid with mild anti-inflammatory and hepatoprotective activity in preclinical work, and it is chosen as the marker for practicality rather than because it is believed to be the principal active. A batch below 0.30% fails the monograph regardless of how convincing the root looks.

Oleanane-type triterpenoid saponins (oleanolic acid and hederagenin glycosides)

Triterpenoid saponin glycosides

Concentration: The characteristic bulk constituent class of Clematidis roots and rhizomes; more than 200 compounds have been reported across the three official species.

The saponin fraction is the usual explanation for both the anti-inflammatory activity and the mucosal irritancy of the drug, and those two properties are not separable. Saponins are surface-active and disrupt membranes, which is consistent with the burning and swelling of the mouth that the toxicology literature records for overdose, and with the traditional practice of decocting the herb with vinegar and swallowing it slowly when it is used to soften a bone lodged in the throat.

Guaianolide sesquiterpenoids with 5/7/5-fused rings and 3S configuration

Guaianolide sesquiterpene lactones

Concentration: Three previously undescribed guaianolides were isolated from a 60% aqueous ethanol extract of the roots and rhizomes of this species in 2020.

Notable because they are species-specific chemistry rather than genus boilerplate: this class had not been the expected profile for a Clematis root, and the compounds were characterised from this species in particular. Sesquiterpene lactones as a class are reactive Michael acceptors and are the usual chemical basis for both anti-inflammatory activity and contact sensitisation in plants that carry them. No pharmacology beyond the isolation paper's own assays has been published for these particular molecules.

Prenylated tetra-substituted phenolic glycosides with benzopyran and dihydro-benzoxepin skeletons

Prenylated phenolic glycosides

Concentration: Five previously undescribed compounds of this class were isolated from the roots and rhizomes of this species in the same 2020 study, alongside a new isoferulyl glucoside and two new furofuran lignan diglucosides.

Structurally unusual, including a 6/6-fused 9H-benzopyran and three 6/7-fused 7,10-dihydro-benzoxepin skeletons, with a proposed biosynthetic route. In the study's in vitro assays one of the isolated compounds inhibited TNF-alpha secretion with an IC50 of 3.419 micromolar and inhibited the phosphatase PTP1B with an IC50 of 4.623 micromolar, and two others inhibited PTP1B by 48 to 86%. PTP1B inhibition is an insulin-sensitising mechanism, which is not a traditional indication for this drug and should be read as a chemical observation rather than a therapeutic lead.

Protoanemonin and its dimer anemonin, formed from ranunculin

Unsaturated gamma-lactone (protoanemonin) and its cyclobutane dimer (anemonin)

Concentration: Not assayed by the monograph. Ranunculin is a family-level constituent of the Ranunculaceae and is enzymatically converted to protoanemonin when tissue is crushed or macerated; drying and heating drive protoanemonin to the far less irritant dimer anemonin, so a properly dried and decocted root delivers much less than fresh plant material.

The standard explanation for the irritant character of Clematis, and the reason fresh Clematis is used as a deliberate blistering agent in folk practice while the dried root is not. Protoanemonin is a vesicant and a mucosal irritant; anemonin is comparatively benign and has been studied for anti-inflammatory and antioxidant effects in its own right. Note the honest limit here: the toxicology review of this drug states plainly that no mechanistic toxicity study exists, so attributing the recorded oral burning and swelling to protoanemonin is a genus-level inference rather than a measurement made on this species.

⚠ Drug Interactions

Unrelated plants sold as wei ling xian, chiefly Veronicastrum sibiricum, Duhaldea nervosa and Smilax species

Major Evidence: Established

The name wei ling xian has never mapped cleanly onto one plant. From the Song to the Qing, physicians commonly dispensed the herbaceous Veronicastrum sibiricum, a plantain-family plant with no botanical relation to Clematis, under this name, and regional practice added Duhaldea nervosa in Yunnan and several Smilax species in the north, the last sold as tie si wei ling xian. The driver was supply: the authentic northern Clematis roots were not available in southern China against high demand. These substitutes remain in the market. Because they belong to three different plant families, none of the saponin, sesquiterpenoid or protoanemonin chemistry of this species can be assumed of them, and neither can its safety profile.

Clinical note: Buy on the oleanolic acid assay, and prefer material identified to species. Where a patient reports taking wei ling xian obtained outside a regulated pharmacy, treat the botanical identity as unknown rather than assuming Clematis. A complete chloroplast genome for this species has been published, so DNA-based authentication is available where the stakes justify it.

Clematis chinensis and Clematis manshurica, the other two official sources of the same drug

Moderate Evidence: Established

The Chinese Pharmacopoeia treats the roots and rhizomes of Clematis chinensis Osbeck, this species, and Clematis manshurica Rupr. as one drug, and material is traded and dispensed interchangeably. The pharmacological literature does not treat them as one. The 2021 review of the drug states explicitly that recent research has focused on C. chinensis and C. manshurica while pharmacological studies of this species are few, and calls for work on this species specifically and on the similarities and differences between the three. Practically, this means that most of what is written about Wei Ling Xian was measured in a different species from the one named here, and that the constituent profiles differ enough that the review had to lay out separate structures for them.

Clinical note: When citing efficacy evidence for Wei Ling Xian, check which species the study used; the answer is usually not this one. Conversely, do not treat the sparse literature on this species as evidence that it is less active, only that it is less studied.

Non-steroidal anti-inflammatory drugs and other gastric irritants, including corticosteroids and alcohol

Moderate Evidence: Possible

The interaction matters because the two are so often taken together: this drug's principal indication is wind-damp painful obstruction, which in modern terms is the arthritis population already on NSAIDs. The documented toxicity of the drug is predominantly mucosal and gastrointestinal. The 2021 toxicology review records that it can cause burning and swelling of the mouth, abdominal pain, severe diarrhoea, difficulty breathing, dilated pupils, structural change in renal tissue, and in severe cases death. Those are overdose findings rather than effects of ordinary therapeutic doses, but they establish that the mucosal margin is not wide. No formal interaction study has been done.

Clinical note: Keep to the pharmacopoeial dose of 6 to 10 g and take after food. Do not exceed it in a patient already on an NSAID, a corticosteroid or a proton pump inhibitor prescribed for gastric protection. Burning in the mouth or throat, or new abdominal pain, is a reason to stop the herb rather than to add a gastroprotectant.

Nephrotoxic drugs, including aminoglycosides, ciclosporin, tacrolimus and high-dose NSAIDs

Theoretical Evidence: Theoretical

Structural change in renal tissue appears in the toxicity findings summarised for this drug, without a dose relationship, a species attribution or a mechanism, because as the same review notes no mechanistic toxicity study has been published. That is a weak basis for a firm warning and a sufficient basis for caution. It is worth separating this from the aristolochic acid problem that affects other herbs sharing partial names with Clematis drugs: there is no suggestion that this species contains aristolochic acid.

Clinical note: Reasonable to check renal function before and during prolonged courses in patients on other nephrotoxic drugs or with existing chronic kidney disease, and to avoid open-ended use. Do not extrapolate the aristolochic acid nephropathy literature to this species; it is a different toxicological question.

Urate-lowering drugs, including allopurinol, febuxostat and benzbromarone

Theoretical Evidence: Theoretical

An aqueous extract of this species and its solvent fractions lowered serum uric acid and improved renal lesions in mice made hyperuricaemic with potassium oxonate and hypoxanthine, with the n-butanol fraction most active and effects attributed to PI3K, AKT and NF-kappaB signalling together with changes in gut microbiota. This is a mouse study and the first of its kind for this species, so it establishes an effect in rodents and nothing about people. It is recorded because gout and wind-damp painful obstruction overlap heavily in practice, so co-administration with a urate-lowering drug is likely rather than hypothetical.

Clinical note: No dose change is warranted on rodent data. If a patient on urate-lowering therapy starts this herb, a urate level at the next routine check is a proportionate response.

Dosage Calculator

⚖ Dosage Calculator

A weight-based mathematical estimate for Clematis hexapetala. Not a prescription.

Evidence Tier

4 studies on record

Recorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.

Systematic review / meta-analysis

0

Randomized controlled trial

0

Other clinical trial

0

Observational / case report

0

In vitro / animal

3

3 verified · 0 unverified

Show 3 studies

Extract of Clematis hexapetala regulates uric acid metabolism, alleviates renal inflammation and fibrosis via the PI3K/AKT/NF-κB signaling pathway, and improves hyperuricemia in mice
Sesquiterpenoids, phenolic and lignan glycosides from the roots and rhizomes of Clematis hexapetala Pall. and their bioactivities
Thermal and wine processing enhanced Clematidis Radix et Rhizoma ameliorate collagen Ⅱ induced rheumatoid arthritis in rats

Other / unclassified

1

1 verified · 0 unverified

Show the study

Uses, chemical compositions, pharmacological activities and toxicology of Clematidis Radix et Rhizome- a Review

Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description

Clinical Studies

Uses, chemical compositions, pharmacological activities and toxicology of Clematidis Radix et Rhizome- a Review

Lin TF, Wang L, Zhang Y, Zhang JH, Zhou DY, Fang F, Liu L, Liu B, Jiang YY (2021) Journal of Ethnopharmacology systematic review Verified: Other / unclassified

The standard reference for this drug and the most useful single source on what is and is not known about this species. It surveys ancient and modern texts, the Chinese Pharmacopoeia, dissertations and the major databases from 1965 to 2020 for all three official Clematis species. More than 200 compounds are catalogued and the differences in composition between the species are laid out structurally. Two conclusions bear directly on this record. First, on toxicology: overdose is reported to cause burning and swelling of the mouth, abdominal pain or severe diarrhoea, difficulty breathing, dilated pupils, structural change in renal tissue, and death, and no study of the mechanism of that toxicity has been published. Second, on species: the authors state that recent research has concentrated on Clematis chinensis and Clematis manshurica and that pharmacological reports on this species are few, and they call for it to be studied in its own right.

DOI: 10.1016/j.jep.2021.113831 Link

Extract of Clematis hexapetala regulates uric acid metabolism, alleviates renal inflammation and fibrosis via the PI3K/AKT/NF-κB signaling pathway, and improves hyperuricemia in mice

Wang W, Min Z, Luo C, Yang M, Chen L (2026) Journal of Ethnopharmacology animal Verified: In vitro / animal

One of the few pharmacological studies carried out on this species specifically rather than on Clematidis Radix generally. Hyperuricaemia was induced in mice with potassium oxonate and hypoxanthine, and the aqueous extract was compared with its petroleum ether, ethyl acetate and n-butanol fractions, characterised by UHPLC coupled to Orbitrap mass spectrometry and dominated by flavonoids and phenolic acids. High-dose n-butanol fraction significantly lowered serum uric acid and improved renal lesions, with mechanistic work implicating PI3K, AKT and NF-kappaB signalling and 16S sequencing showing changes in gut microbiota. Mouse work only, with a strong network-pharmacology component; it does not establish efficacy in gout or hyperuricaemia in patients.

DOI: 10.1016/j.jep.2026.121698 Link

Sesquiterpenoids, phenolic and lignan glycosides from the roots and rhizomes of Clematis hexapetala Pall. and their bioactivities

Cai L, Shao SY, Han SW, Li S (2020) Bioorganic Chemistry in vitro Verified: In vitro / animal

The reference phytochemical study of this species. Seventeen compounds were isolated from a 60% aqueous ethanol extract of the roots and rhizomes, eleven of them new: three guaianolide sesquiterpenoids with 5/7/5-fused rings, five prenylated tetra-substituted phenolic glycosides with benzopyran and dihydro-benzoxepin skeletons, an isoferulyl glucoside and two furofuran lignan diglucosides. Structures were settled by spectroscopy, electronic circular dichroism and a modified Mosher's method. In cell assays one compound inhibited TNF-alpha secretion with an IC50 of 3.419 micromolar and PTP1B with an IC50 of 4.623 micromolar, and three compounds inhibited PTP1B by 48 to 86%. Chemistry with screening assays, not a therapeutic study.

DOI: 10.1016/j.bioorg.2020.104312 Link

Thermal and wine processing enhanced Clematidis Radix et Rhizoma ameliorate collagen Ⅱ induced rheumatoid arthritis in rats

Jiang SQ, Pan T, Yu JL, Zhang Y, Wang T, Li P, Li F (2022) Journal of Ethnopharmacology animal Verified: In vitro / animal

Addresses the processed drug, which is how this herb is often actually dispensed. Crude and wine-processed Clematidis Radix et Rhizoma were compared in lipopolysaccharide-stimulated RAW264.7 macrophages and in collagen-induced arthritis rats. Both reduced nitric oxide and both lessened inflammatory infiltration and cartilage erosion; both suppressed glycolysis by downregulating PKM2, lowering glucose uptake and lactate and normalising reactive oxygen species and mitochondrial membrane potential, with PI3K-AKT and HIF-1alpha implicated by network pharmacology. Both also shifted the caecal microbiota toward Firmicutes and away from Bacteroidetes. The study is on the multi-species drug rather than on this species alone, so it should not be read as evidence about Clematis hexapetala in particular.

DOI: 10.1016/j.jep.2022.114993 Link

Historical Texts

Kaibao Bencao (Materia Medica of the Kaibao Era), imperially commissioned, Liu Han and Ma Zhi

Northern Song dynasty, 973 to 974

The earliest text to carry wei ling xian, describing it as bitter, warm and non-toxic. Two things about that entry matter now. The taste and nature it assigns, bitter and warm, is not what the modern pharmacopoeia assigns, which is acrid, salty and warm, and the identity it intends is almost certainly not this plant: from the Song onward physicians widely dispensed the plantain-family herb Veronicastrum sibiricum under the name. The Clematis identity that the Chinese Pharmacopoeia now fixes was settled centuries after the drug's first appearance, so the classical indications and the modern species are joined by convention rather than by continuous documentation.

Bencao Gangmu (Compendium of Materia Medica), Li Shizhen

Ming dynasty, completed 1578, first printed 1596

Explains the name as a compound claim about the drug: wei speaks of the fierceness of its nature and ling xian of the divine quality of its effect. Li Shizhen also records its use for a bone lodged in the throat, the indication that still attaches to the herb and that survives into modern practice as a single-herb decoction of about 15 g, sometimes prepared with rice vinegar and swallowed slowly rather than drunk. The etymology is a warning as much as praise; a drug named for the fierceness of its nature is one to keep at its stated dose.

Zhonghua Renmin Gongheguo Yaodian (Pharmacopoeia of the People's Republic of China), monograph for Weilingxian, Clematidis Radix et Rhizoma

Modern; the text described here is the 2020 edition, Volume I

Defines the drug as the dried root and rhizome of Clematis chinensis Osbeck, Clematis hexapetala Pall. or Clematis manshurica Rupr., known in Chinese respectively as wei ling xian, mian tuan tie xian lian and dongbei tie xian lian. It is acrid, salty and warm, dispels wind-dampness and unblocks the channels and collaterals, and is indicated for wind-damp painful obstruction, numbness of the limbs, constrained sinews and difficulty in flexion and extension. The stated dose is 6 to 10 g, and the assay requires not less than 0.30% oleanolic acid on the dried basis. The monograph is what makes this species an official drug at all; without it the plant would sit outside the Chinese materia medica under its own name.

References

Cui Y, Sun Y, Ding Y, Liu J, Han Z, Wang Y, Han M, Yang L. The complete chloroplast genome of Clematis hexapetala (Ranunculaceae) and its phylogenetic analysis . Mitochondrial DNA Part B (2022) [DOI]
Ma Z, Yu P, Li X, Dai F, Jiang H, Liu J. Anemonin reduces hydrogen peroxide-induced oxidative stress, inflammation and extracellular matrix degradation in nucleus pulposus cells by regulating NOX4/NF-κB signaling pathway . Journal of Orthopaedic Surgery and Research (2023) [DOI]

Clematis hexapetala

Safety at a glance

Traditionally used for

Cautions & contraindications