# Motherwort (Leonurus cardiaca)

**Cardiaca*; lion’s tail*

**Known today as.** *Leonurus cardiaca*, of the mint family, a tall, prickly-calyxed herb of waste ground.

Kind: Plant

## What was it used for?

For the heart, as its Latin name says: for palpitations and faintness, and for the womb, in childbirth and its aftermath.

## What does modern science say?

Small studies suggest a mild calming effect; its use for the heart has no good clinical support.

## Pharmacognosy and toxicology

- **leonurine**: an alkaloid
- **stachydrine**: 
- **ajugoside and other iridoids**: 
- **lavandulifolioside**: 

**Mechanism.** Mildly sedative and slows the heart in animal preparations, which is as near as the herbals’ “cardiaca” came to a test; leonurine contracts the uterus in animals, the basis of the Chinese use (yi mu cao) after childbirth, and is studied for cardioprotection.

**Dose.** Safe at tea doses; not in pregnancy, for the uterine action.

**Standing.** EMA monograph (2010) for nervous cardiac complaints and sleep, on tradition; in the Chinese Pharmacopoeia for menstrual and postpartum use.

## What lore surrounds it?

Folkard has Parkinson's reason for the name, “of wonderful helpe to women in the risings of the mother,” and the Japanese festival on the 9th of the 9th month, “called the Festival of Motherwort,” with its zakki brewed from the flowers and the legend of the boy emperor who, told he would die before fifteen, drank it daily “and lived upwards of seventy years.” In the houses of the common people “a branch of the flowers fastened with a string to a pitcher full of common zakki” wishes the household long life.

## What did the older authorities say?

**Culpeper.** Writes that there is no better herb “to drive melancholy vapours from the heart, to strengthen it, and make a merry, cheerful, blithe soul.”

## Sources

- Culpeper, N. (1652). *The English Physitian*.
- Grieve, M. (1931). *A Modern Herbal*, “Motherwort.”
- Folkard, R. (1884). *Plant Lore, Legends, and Lyrics*, “Motherwort.” Project Gutenberg #44638.
- EMA/HMPC (2010). *Community herbal monograph on Leonurus cardiaca L., herba* (EMA/HMPC/127428/2010).
- Shang, X., et al. (2014). “*Leonurus japonicus* Houtt.: ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine.” *Journal of Ethnopharmacology* 152.

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*Motherwort.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/motherwort

Historical description, not medical advice.