Chong Wei Zi
StarLeonurus japonicus Houtt.
Traditionally used for
- Eye health
- Urinary & fluids
- Menstrual & women's health
Cautions & contraindications
- Pregnancy
- Liver conditions
☯ TCM Properties
Invigorates Blood and Regulates Menstruation; Clears Liver Heat and Brightens the Eyes; Disperses Wind-Heat; Promotes Urination and Reduces Edema
Traditional Chinese Uses
Chong Wei Zi (leonurus fruit, motherwort fruit) is a cool herb with the same Blood-activating, menstrual-regulating channel as its better-known counterpart Yi Mu Cao (motherwort herb). It is used for menstrual irregularities, painful menstruation, and Blood stasis patterns affecting the uterus. It also has a significant eye-brightening application — clearing Liver Heat to relieve red, swollen eyes and visual disturbances, which distinguishes it clinically from the leaf and stem preparation.
Relationships
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Botanical Description
Leonurus japonicus is an erect annual or biennial herb in the Lamiaceae, reaching 60-120 cm with a square, finely pubescent stem. The lower leaves are long-petiolate and palmately three- to five-lobed; upper stem leaves become progressively narrower and deeply divided into linear segments. Small pinkish to pale purple two-lipped flowers are borne in dense axillary verticillasters along the upper stem. Each flower produces four small, three-sided, brown-grey nutlets (achenes) about 2-3 mm long enclosed by the persistent spiny calyx. These dried ripe fruits, harvested in autumn when the lower fruits ripen, constitute the medicinal Chong Wei Zi. The species is widespread across East Asia in fields, roadsides, and waste ground.
Active Constituents
Stachydrine (proline betaine)
Pyrrolidine alkaloid (quaternary ammonium betaine)Concentration: the Chinese Pharmacopoeia assay for Leonuri Fructus (Chong Wei Zi) requires not less than 0.050% stachydrine hydrochloride in the dried ripe fruit
Stachydrine is the pharmacopoeial marker for both the fruit and the aerial herb of this species and is the compound most consistently detected in the fruit by TLC-MS. It has no UV chromophore, so it cannot be assayed by ordinary HPLC-UV and is quantified by qNMR, HPTLC or derivatisation methods. Reported activities are cardiovascular, hypotensive and tissue-protective rather than the strong uterotonic action usually attributed to the drug.
Leonurine (SCM-198)
Guanidino-alkaloid (4-guanidinobutyl syringate ester)Concentration: unambiguously demonstrated for the aerial parts (Yi Mu Cao); its presence and content in the officinal fruit have been questioned rather than established
Leonurine carries most of the uterotonic, hypotensive, cardiovascular and neuroprotective activity credited to Leonurus drugs, and reviews of its pharmacokinetics show extensive phase II conjugation after oral dosing. A dedicated HPLC study noted that leonurine had only been proven unambiguously in the aerial parts of L. japonicus, and that the same could not be said for the officinal fruits (chongweizi) or for European L. cardiaca, so a monograph claim of leonurine content in the fruit should be treated as unconfirmed rather than assumed.
Total Leonurus alkaloid fraction
Mixed alkaloid fraction (betaines plus guanidino alkaloids)The combined alkaloid fraction of L. japonicus is angiogenic in the zebrafish embryo model and suppresses endometrial inflammation in rodents, reducing pro-inflammatory signalling in the uterus. This fraction, not any single compound, is what the injectable Chinese preparations are standardised against.
Volatile (essential) oil of L. japonicus
Essential oil (mixed terpenoid and aliphatic volatiles)Unlike the alkaloid fraction, the essential oil of this species is frankly toxic to zebrafish embryos in the same experimental system, which is a reason to distinguish alcohol or water preparations from oil-rich ones. This matters for the fruit in particular, since fruits and seeds concentrate lipophilic material.
⚠ Drug Interactions
Oxytocin and other uterotonics (carboprost, methylergometrine)
Leonurus japonicus preparations are uterotonic, and the effect is additive with oxytocin rather than merely parallel. A 2025 integrated analysis combining real-world cesarean-section records, a meta-analysis of randomised trials and animal validation found that motherwort injection given alongside oxytocin improved prevention of postpartum haemorrhage over oxytocin alone. Note that every one of these studies used motherwort injection prepared from the aerial parts (Yi Mu Cao, Leonuri Herba), not the fruit.
Clinical note: Deliberate co-use is standard Chinese obstetric practice, but outside that setting treat any Leonurus preparation as a uterine stimulant: do not add it to a patient already receiving a uterotonic without an obstetric indication, and do not give it in pregnancy.
Pregnancy (uterine stimulation)
Leonurine is a documented uterotonic, and the clinical use of L. japonicus preparations is precisely to contract the postpartum or post-abortion uterus and reduce bleeding. Randomised evidence exists for motherwort injection preventing uterine haemorrhage after induced abortion. The same pharmacology makes the drug unsuitable during pregnancy.
Clinical note: Contraindicated in pregnancy. Chong Wei Zi is a blood-invigorating drug in the same class as Chuan Xiong and E Zhu and should be withheld once pregnancy is known or suspected.
Leonurus cardiaca and Leonotis leonurus (substitution hazard)
European motherwort (Leonurus cardiaca, Ph.Eur.) and South African Leonotis leonurus are sold and cited as if interchangeable with the Chinese drug. Comparative HPLC and qNMR work by the same group showed that leonurine, the principal active constituent claimed for these drugs, is proven only for the aerial parts of L. japonicus, and that stachydrine contents differ markedly between the three species and between fruit and herb. A European motherwort supplement is therefore not a source of Chong Wei Zi.
Clinical note: Verify the botanical source and the plant part. Chong Wei Zi is the dried ripe fruit of L. japonicus; Yi Mu Cao is the aerial part of the same plant, and the two are separate pharmacopoeial drugs with different assay markers and different clinical uses.
Antihypertensive drugs
Both stachydrine and leonurine are described as hypotensive and cardiovascularly active in the pharmacological literature, but no human interaction study with antihypertensive drugs has been published for either the fruit or the herb.
Clinical note: No dose change is required on present evidence; check blood pressure if a patient on multiple antihypertensives starts a Leonurus preparation.
Warfarin, direct oral anticoagulants and antiplatelet agents
Chong Wei Zi is classified as a blood-invigorating drug and Leonurus alkaloids are angiogenic and vasoactive in preclinical models. No pharmacokinetic or pharmacodynamic interaction study with an anticoagulant has been published, so this remains an inference from drug class rather than a measured interaction.
Clinical note: Flag it, do not treat it as established. If a patient on an anticoagulant takes Chong Wei Zi, monitor for bruising and check INR at the usual intervals.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 5–10 g | Daily | — | — | 中国药典 2020 【用法与用量】5～10g。 【注意】瞳孔散大者慎用。 【性味与归经】辛、苦，微寒。归心包、肝经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Strong evidence · 6 studiesRecorded 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
2
2 verified · 0 unverified
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
1
0 verified · 1 unverified
In vitro / animal
3
1 verified · 2 unverified
Show 3 studies
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Motherwort synergized with oxytocin for postpartum hemorrhage prevention: Integrated clinical efficacy and mechanism exploration
Combined real-world electronic-health-record data from a high-risk pregnancy referral centre, a meta-analysis of randomised trials and animal validation. Motherwort injection added to oxytocin improved prevention of postpartum haemorrhage at cesarean section compared with oxytocin alone, and the active constituents of the injection were characterised by UPLC-HRMS. The preparation studied is made from the aerial parts of Leonurus japonicus (Yi Mu Cao), not from the fruit Chong Wei Zi.
Effects of Motherwort Injection Versus Intramuscular Oxytocin for Preventing Postpartum Hemorrhage Among Women Who Underwent Cesarean Section
Compared motherwort injection with intramuscular oxytocin for prevention of postpartum haemorrhage in women delivering by cesarean section. Again the material is the aerial-part preparation, so the result supports Yi Mu Cao rather than Chong Wei Zi.
Motherwort Injection for Preventing Uterine Hemorrhage in Women With Induced Abortion: A Systematic Review and Meta-Analysis of Randomized Evidence
Meta-analysis of randomised trials of motherwort injection for preventing uterine bleeding after induced abortion. Demonstrates the uterotonic and haemostatic effect of the aerial-part preparation in a gynaecological setting; it is also the clearest published reason to regard any Leonurus preparation as contraindicated during pregnancy.
Effect of Leonurus japonicus alkaloids on endometrial inflammation and its mechanisms
The total alkaloid fraction of L. japonicus reduced endometrial inflammation in a rodent model, with mechanistic work on the inflammatory signalling involved. Supports the traditional gynaecological indication at the level of the alkaloid fraction of the plant.
Angiogenic effect of motherwort (Leonurus japonicus) alkaloids and toxicity of motherwort essential oil on zebrafish embryos
In the zebrafish embryo model the alkaloid fraction of L. japonicus promoted angiogenesis while the essential oil of the same plant was toxic to the embryos. A useful safety separation: the water-soluble alkaloid fraction and the volatile oil of this species behave very differently.
1H-qNMR for direct quantification of stachydrine in Leonurus japonicus and L. cardiaca
Developed a direct quantitative 1H-NMR method for stachydrine, which lacks a UV chromophore and is therefore difficult to assay by conventional HPLC-UV. Nine samples from three countries prepared as freeze-dried decoctions showed stachydrine contents spanning more than an order of magnitude, which is a concrete warning about batch-to-batch variability in Leonurus drugs.
⚠ Safety & Contraindications
- Pregnancy
- Liver conditions
Contraindications
Its use is prohibited in pregnant women or patients with insufficiency of liver blood or mydriasis.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 237–243.
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyBen Cao Gang Mu
Ming dynasty, 1596References
- Liu S, Sun C, Tang H, Peng C, Peng F. Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology . Frontiers in Pharmacology (2024) [DOI]
- Zhang N, Wang M, Li Y, Zhou M, Wu T, Cheng Z. TLC–MS identification of alkaloids in Leonuri Herba and Leonuri Fructus aided by a newly developed universal derivatisation reagent optimised by the response surface method . Phytochemical Analysis (2021) [DOI]
- Kuchta K, Ortwein J, Rauwald HW. Leonurus japonicus, Leonurus cardiaca, Leonotis leonurus: A novel HPLC study on the occurrence and content of the pharmacologically active guanidino derivative leonurine . Die Pharmazie (2012) [DOI]
- Kuchta K, Volk RB, Rauwald HW. Stachydrine in Leonurus cardiaca, Leonurus japonicus, Leonotis leonurus: detection and quantification by instrumental HPTLC and 1H-qNMR analyses . Die Pharmazie (2013) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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