Leonurus japonicus, commonly called Chinese motherwort, is a herbaceous flowering plant native to Asia, including Korea and Japan, China to Cambodia. It has escaped cultivation and become naturalized in other parts of the world including South and North America, Europe and Africa. It is one of the 50 fundamental herbs used in traditional Chinese medicine, where it is called yìmǔcǎo (益母草), literally "beneficial herb for mothers".
Indication: Menstrual disorders, delayed or absent menses, irregular menses, amenorrhea, dysmenorrha, endometriosis, infertility, PMS, lower abdominal pain, placenta leakage, dystocia, retained placenta, postpartum abdominal pain due to blood obstruction, postpartum pain and bleeding, hematuria, hypertension, nephritis, kidney stones, edema, dysuria, hematuria (blood in urine), lump in the breast, skin infections, skin eruptions.
The leaves are diuretic and are placed in bath water to relieve itching and painful shingles.
The dried flowers are emmenagogue and are also used in pregnancy and to help expel the placenta after giving birth.
The juice of the stems is vulnerary.
The seed is aphrodisiac, diuretic, emmenagogue, ophthalmic and is also used in the treatment of various women's complaints. The plant was ranked number one in a survey of 250 potential antifertility plants in China. The seed is used in the treatment of conjunctivitis and night blindness.
The whole plant is decocted, either on its own or with other herbs, as an ophthalmic. It is used in the treatment of abnormal menstruation, postpartum abdominal pain, tumours, uterine bleeding, oedema, eczema and purulent abscess. It is also used externally as a poultice for bruises.