Employed by the ancient Greeks to reduce anxiety during childbirth, motherwort (Leonurus cardiaca) is primarily used as a tea or tincture for its potential medicinal properties (1Trusted Source).
Also called lion’s tail, motherwort is an upright, prickly bush with dark green leaves and furry purple or pink flowers (1Trusted Source).
It’s native to Asia and Southeastern Europe but can now be found worldwide. In the United States, it’s considered an invasive species (2).
Unlike some other herbs in the mint family, it has an unpleasant smell and bitter flavor.
This article reviews motherwort, including its potential benefits and side effects.
Potential benefits of motherwort
Motherwort has been used for thousands of years to treat various conditions, including heart disease, anxiety, and irregular menstruation (1Trusted Source).
Though many of its traditional uses have not been scientifically studied, research indicates that the herb has some potential health benefits.
Motherwort contains numerous plant-based compounds with antioxidant properties, including flavonoids, sterols, triterpenes, and tannins (3, 4Trusted Source, 5Trusted Source, 6Trusted Source).
Antioxidants are compounds that protect your cells from damage caused by potentially harmful molecules known as free radicals (7Trusted Source).
Research shows that antioxidants may help protect against several conditions, including cancer, arthritis, heart disease, Alzheimer’s, and Parkinson’s (7Trusted Source).
May lower heart rate and blood pressure
One traditional use of motherwort is to help reduce rapid or irregular heart rate caused by stress or anxiety.
In test-tube and animal studies, motherwort extract exhibited antiarrhythmic effects, suggesting that it could help lower elevated heart rate. However, these effects have not been observed in humans (8Trusted Source).
One 28-day study in 50 adults with high blood pressure and anxiety observed that supplementing with motherwort extract reduced heart rate, but the change was insignificant (9Trusted Source).
However, the findings noted significant improvements in blood pressure levels. Still, the study was quite small, and similar results have not yet been replicated (9Trusted Source).
Despite limited research, some European countries have approved the use of motherwort to support heart health and help treat hyperthyroidism, stress, and anxiety (10).
May aid heart health
Ursolic acid, leonurine, and flavonoids are compounds in motherwort that have exhibited heart-protective effects in rat studies. Yet, these results have not been confirmed in humans. (11Trusted Source, 12Trusted Source, 13Trusted Source, 14Trusted Source).
Nevertheless, while not specific to flavonoids in motherwort, observational studies in humans have shown a relationship between total flavonoid intake and a decreased risk of developing and dying of heart disease (15Trusted Source, 16Trusted Source).
Other potential benefits
While research is limited, motherwort may offer additional benefits, including:
May reduce postpartum blood loss. Early research suggests that treatment with motherwort and oxytocin may significantly reduce the risk of postpartum blood loss, compared with oxytocin alone (17Trusted Source).
May alleviate anxiety and depression. While limited in scope, early human and rat studies show a reduction in symptoms of anxiety and depression after taking motherwort or leonurine extracts daily for up to 4 weeks (9Trusted Source, 18Trusted Source).
May decrease inflammation. Test-tube and animal studies have found that the leonurine in motherwort has anti-inflammatory properties. However, these results haven’t been confirmed in humans (19Trusted Source, 20Trusted Source).
Possible side effects
Current research on motherwort’s effects in humans is limited. As a result, the herb’s safety and potential side effects are not fully understood.
Based on recent findings, the potential side effects of consuming excess motherwort include diarrhea, uterine bleeding, and stomach pain (10, 19Trusted Source)
Given that motherwort has the potential to affect heart rate and rhythm, those on heart rate medications, such as beta-blockers, and people with low blood pressure should consult their healthcare provider before trying this supplement (19Trusted Source).
Furthermore, the herb has been shown to interact with the blood thinner warfarin and should not be taken by anyone on blood-thinning medication unless cleared by a medical professional (21Trusted Source).
Finally, due to a lack of research and its potential to stimulate uterine contractions, women who are pregnant or breastfeeding are also advised to avoid motherwort (10).