Leonurus cardiaca is a perennial plant indigenous to central Europe and Scandinavia, but it is also found in the area spanning temperate Russia to central Asia. It has been introduced to North America and has become established locally in the wild. Motherwort (Leonuri cardiacae herba) consists of aerial parts of Leonurus cardiaca gathered during the flowering period, dried at 35 °C and, according to European Pharmacopoeia 7th edition, should contain a minimum of 0.2% flavonoids, expressed as hyperoside. Compounds belonging to the group of monoterpenes, diterpenes, triterpenes, nitrogen- containing compounds, phenylpropanoids, flavonoids and phenolic acids, as well as volatile oils, sterols and tannins, have been identified in motherwort. Traditionally, extracts of the herb have been used internally, mainly for nervous heart conditions and digestive disorders. However, they have also been used for bronchial asthma, climacteric symptoms and amenorrhoea, as well as externally in wounds and skin inflammations. Mild negative chronotropic, hypotonic and sedative effects can be attributed to the herb and preparations thereof. Pharmacological studies have confirmed its antibacterial, antioxidant, anti-inflammatory and analgesic activity, as well as its effects on the heart and the circulatory system. Sedative and hypotensive activity has been demonstrated in clinical trials.