Leaves.
The remedy made from the horehound plant is extremely effective in the treatment of problems such as wheezing, and chronic bronchitis, it is also used in alleviating bronchiectasis - which is induced by a damaged air passage inside the lung. This remedy is recommended for the treatment of bronchial asthma, to ease chronic hacking coughs, and to bring relief from whooping cough - that affects children in particular. One of the specific effects of the remedy made from the horehound is to induce the secretion of much more fluid like mucus in the mucous glands - this type of fluid is easier to clear from the body by the act of coughing. The remedy made from the horehound is considered to be a major herbal bitter tonic, and is given to patients to increases their appetite and to boost the functioning of the stomach and digestive system in general. The rhythm of the heart is also normalized by the action of the horehound herb, the remedy helps improve the regularity of the cardiac contraction. The decoction made from the horehound herb is also used for some skin conditions - though the application of the herb in this role is rare in current herbal practice. Different parts of the herb have different beneficial effects, thus, the leaves and the tender flowering stems possess an anti-septic and anti-spasmodic effect, these also contain compounds that are cholagogue and diaphoretic, compounds that aid digestion and are diuretic. The herb also has emmenagogue, strongly expectorant and tonic effects. It is considered to be a hepatic and stimulatory herb. The safety of this herb is undisputed and it can be safely used on children, it is particularly effective as a pectoral, expectorant and tonic for adults and children affected by respiratory problems. One common way in which the horehound is used, is in the form of an herbal syrup or candy - this is a way to disguise the otherwise very bitter flavor of the herb. However, for those who prefer it, it can be taken as an herbal tea as well. Horehound can be used dried or fresh; plants are harvested immediately before the floral bloom in the summer. Horehound root is a valuable herbal remedy for treating the bite of rattlesnakes and other venomous animals - in this role, the herb is combined with the Plantago lanceolata or P. major herbs in equal proportions.
The horehound is an indigenous European plant; it also grows wild in North and South America and has been naturalized. The types of habitats where the horehound can be found include dry, barren, or open areas and wastelands. The horehound plants are normally harvested during the spring season and dried to be used in various herbal remedies. The horehound is a perennial plant, except in regions with cold climates where plants may die off each winter. An easy plant to grow and cultivate, the white horehound can successfully grown in most soil types as long as they are well drained and without the danger of water logging. Ideal growth can be observed in dry soil poor in nutrients. There are also scientific studies that state that soils rich in nitrogen may be ideal for growing the horehound. For optimum growth, the horehound prefers soils that are neutral or slightly alkaline. The site must also be warm with a good exposure to sunlight. The horehound is a very common cultivar in many herb gardens, being at times cultivated as a medicinal herb on a commercial scale in some areas. The horehound plant will bring forth a second crop of leaves if properly trimmed and cut back after an initial floral bloom. A strong and musky smell is always present on the fresh leaves, this smell tends to disappear in the dried herb. The horehound is preferred by bees and a favorite of many apiarists. The horehound is ideal as a partner plant for tomatoes in the garden. When grown alongside the tomato, the tomato plants tend to have higher yields and crop for a longer period of time - for reasons that are still unclear. The horehound is usually propagated using stocked seeds. The seeds are normally sown in seedbeds on a cold frame during the spring, April or in May and at times in the fall, August or September. The rate of germination is not good for this plant, and is slow and erratic in most cases. When the seedlings emerge from the soil and turn large enough to handle, each seedling must be pricked out into single pots. These pots are then to be plant out in the spring of the following year. The cuttings from the base of the plant are carried out late in the spring. To take cuttings, the shoots must be harvested along with plenty of attached underground stem - this must be done when the plants are eight to ten cm above the soil bed. The cuttings may be potted up singly and then kept in light shade on a cold frame or grown inside a greenhouse - till they begin to root well in the soil. The horehound seedlings emerging from cutting can be planted out doors in the summer of the following year. The division must be done in the spring. When dividing, the large clumps may be transplanted direct into the permanent site, as for the smaller clumps, it may be best to grow them on a cold frame till they start to root well in the soil. These plantlets can then be transplanted out to the permanent site in the spring of the following year.
Horehound contains the diterpenes marrubiin (0.3-1.0%) and marrubenol, flavonoids, alkaloids (including betonicine and stachydrine), and 0.6% volatile oil. Marrubiin is strongly expectorant and bitter.