Black Horehound has a short, creeping rhizome with a simple or branched stem that reaches a height of 100-120cm. The stem of the plant is hairy, four-sided, initially green, but eventually turns red-violet. The spreading, long branches are covered with serrated, dark green leaves, they are ordinary, pointed, ovate on short petioles, which reach 5-8cm in length and 3-6cm in width.
Flowers double-lipped, rosy purple or dirty pink. Fruits - cylindrical or oval black nuts, up to 2 mm long.
The above-ground part of the plant is used for medicinal purposes. The tops of the plant are cut during flowering, June-August. Spread in a thin layer on sieves and dry in a shady and well-ventilated place, stirring occasionally. The unpleasant smell of the plant disappears during drying. The drug is stored hidden from the sun for no longer than 2 years.
This plant has also been studied in the laboratory and determined to contain phenols and organic acids, flavonoids, alkaloids, diterpenes (marubin and ballotinone), phytosterols, up to 13% tannins, choline, tannins, bitter substances and pectins.
The medicinal value of the plant is determined by the substances it contains. Diterpenes have an antispasmodic effect on smooth muscles, phenolic acids act as antioxidants, and also have anti-inflammatory and antimicrobial effects. Flavonoids produce anti-edematous and hemolytic effects. French scientists, conducting experiments with this plant on animals, determined its neuro-sedative properties.
In folk medicine, extracts and decoctions from the black Horehound are used against insomnia, to reduce tension, relieve chest pain and reduce arterial blood pressure. As a diuretic, the extract of this plant is used to reduce edema of various etiologies. Decoctions are considered effective against menstrual, muscle and joint pain. In addition, in case of muscle pain, it is recommended to add the decoction to the bath water. Decoctions are also used for sciatica and rheumatism.