Yi Mu Cao (Chinese Motherwort)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Yi Mu Cao?

  Roughly 9–15 g in decoction, with a stated maximum of 30 g — Bensky and Chen give overlapping ranges (9–15 g and 10–15 g respectively), both capping at 30 g given the herb’s mild alkaloid toxicity at high doses (see Toxicity).

  Source: Sacred Lotus sources & references (Bensky, Materia Medica; Chen & Chen). Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Yi Mu Cao, especially in pregnancy?

  Yi Mu Cao requires strict caution in pregnancy — as a strong Blood-invigorating, stasis-dispelling herb it carries a real risk of stimulating uterine contraction and is traditionally avoided or used only under close practitioner supervision during pregnancy. It should also not be used in Blood- and Yin-deficient patients, nor in Yang-deficient patients with prolapse.

  • Pregnancy — use strict caution; this is the herb’s most important safety caveat and is consistent across classical and modern sources.
  • Pattern contraindications — avoid in Blood/Yin deficiency and in Yang-deficient prolapse patterns, where its moving, draining action can aggravate deficiency.

  Source: Sacred Lotus sources & references (Bensky, Materia Medica; Chen & Chen).

Chinese Herb Toxicity & Overdose

• Slightly toxic at high doses due to its alkaloid content — the Sacred Lotus safety record notes that excess intake can cause sudden general weakness, stiffness, paralysis, general body pains, an oppressive sensation in the chest, excess sweating, low blood pressure, cold extremities, shock, cyanosis, respiratory paralysis, and (in pregnancy) miscarriage. This underlines the importance of staying within the stated dose ceiling (see Dosage) and the strict pregnancy caution above.

  Source: Sacred Lotus sources & references. Reference note, not a safety guarantee.

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Yi Mu Cao (Leonurus japonicus)?

  Yes — research on the plant and its principal alkaloid, leonurine, spans traditional gynecological pharmacology, cardiovascular protection in preclinical models, and a clinical trial supporting its classic postpartum use.

  • Postpartum hemorrhage (clinical trial) — a 2025 study found that motherwort injection combined with oxytocin reduced postpartum bleeding at 2 and 24 hours and roughly halved postpartum hemorrhage risk compared with oxytocin alone, with mechanism work pointing to the alkaloid stachydrine increasing calcium-mediated uterine smooth-muscle contraction; this directly supports Yi Mu Cao’s classic postpartum/gynecological indication, though it used an injectable preparation, not the oral decoction.
  • Leonurine pharmacology (preclinical) — reviews describe leonurine’s effects on oxidative stress, inflammation, fibrosis, and cell survival, including protection in hypoxic heart-cell and heart-attack animal models; these are laboratory/animal findings on an isolated compound, not clinical evidence for the whole herb.
  • Ethnopharmacology review — a comprehensive 2014 review of Leonurus japonicus catalogs roughly 140 identified compounds (alkaloids, diterpenes, flavones) and confirms leonurine and stachydrine as the most-studied actives, while noting that formal toxicity research on the whole herb is still limited.

  Clinical evidence is strongest for the postpartum/uterine-contraction use (an injectable extract trial); broader claims remain preclinical.

  Sources: Chen C et al., Phytomedicine 2025, PMID 40527062 (motherwort + oxytocin postpartum hemorrhage trial); Li YY et al., Chin J Integr Med 2020, PMID 31069695 (leonurine review); Shang X et al., J Ethnopharmacol 2014, PMID 24412548 (ethnopharmacology review). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Yi Mu Cao different from Chong Wei Zi, and from Western “motherwort”?

  Yi Mu Cao is the aerial (above-ground) part of the plant, while Chong Wei Zi (Semen Leonuri) is its seed — a related but distinct materia medica entry with its own actions (more focused on brightening the eyes and blood-cooling, with less of Yi Mu Cao’s strong urination-promoting action). The two are not interchangeable in formula design despite coming from the same plant.

  • Not the same species as Western herbal “motherwort” — the TCM herb is Leonurus japonicus (Herba Leonuri), while the plant long used in Western/European herbalism under the name “motherwort” is the related but distinct species Leonurus cardiaca. Both belong to the genus Leonurus and share some alkaloids (e.g. leonurine, stachydrine), but they are different species with separate materia medica traditions and should not be assumed equivalent in dosing or evidence.
  • Formula context — Yi Mu Cao appears in Sacred Lotus’s formula records combined with Liver-calming herbs, for example in Tian Ma Gou Teng Yin, where it supports the formula’s blood-moving, heat-clearing aspect. (Traditional formula context, not treatment advice.)

  Source: Sacred Lotus sources & references (herb and formula records); Shang X et al., J Ethnopharmacol 2014, PMID 24412548 (species/ethnopharmacology); cross-referenced against multiple online sources.