Mentha piperita

Latin Binomial
Mentha piperita

Common Names
English: Peppermint
Chinese: Bo he
French: Menthe

Species Used

Family
Labiatae

Habitat
Cultivated in many parts of the world but grows well in damp and shady areas.

Botanical Description
Fragrant perennial plant with stems up to four feet tall and square. Leaves are opposite, toothed and hairy on the underside. The pinkish flowers are in whorled clusters in the axils of the upper leaves. Flowers rarely produce viable seeds. Propagation is by underground stolons making the plant very spreading in nature. M. piperita is a hybrid of two other mints, possibly spearmint (M. spicata) and water mint (M. aquatica).

Parts Used
Leaves

Historical Uses
Mints have been used worldwide for centuries as medicinal and culinary herbs. M. piperita does not have the same history in the Western world because it is a hybrid and was not grown in England until the mid 1700's. M. piperita is native to the Mediterranean region and may have been cultivated as long ago as the time of the ancient Greeks and Egyptians. Due to its penetrating odor, it has been used as a stimulant and nerve tonic. M. piperita can also be used in treating mouth sores, nausea and impaired digestion. M. spicata, spearmint, also has a pungent volatile oil but is reputed to be less powerful and may be better suited for children and for treatment of general upper respiratory infections.

Constituents
Volatile oils-menthol, menthone, menthyl acetate, menthofuran, limonene, pulegone, cineol and azulenes; flavonoids-methoside and rutin; carotenes-tannins, betaine and choline.

Medicinal Actions
Stimulant, antispasmodic, carminative, diaphoretic, antiseptic, antiemetic.

Medicinal Uses
M. piperita is commonly used for the effects from its volatile oils, mainly menthol. The digestive system benefits greatly from these effects through a number of mechanisms. One way M. piperita works is that the menthol relaxes the lower esophageal sphincter (also known as the cardiac sphincter) to release pressure from the stomach. Another way M. piperita acts on the GI tract is by inhibiting the hyperactivity of intestinal smooth muscle through blocking the influx of calcium into the muscle cell. This helps to regulate the intestines by normalizing muscle function and facilitating the expiration of gas, improving such conditions as irritable bowel syndrome.

M. piperita stimulates digestive secretions through its bitter and choleretic properties. The bitter principle enhances pancreatic secretions and the choleretic effects stimulate the flow of bile and increase the solubility of bile. These effects may stimulate the release and shrinkage of gallstones (M. piperita may be contraindicated in some cases of gallstones. If gallstones are present or if there is a history or symptoms of gallstones, consult a doctor before use.). (Please note that gallstones may be asymptomatic.)

The antiseptic and diaphoretic qualities of M. piperita make it valuable in the treatment of colds and flu. Warm peppermint teas will encourage perspiration and recovery. The volatile oils are antiseptic and antiviral. M. piperita also reduces the catarrh from head colds.

Topically, peppermint oil may be used as a counter irritant to produce analgesic and anti-inflammatory effects. The oils stimulate nerve perception of cold while pain perception is decreased. To the skin this feels like an initial sensation of cool, followed by warmth. This treatment is useful in musculoskeletal conditions, headaches and toothaches.

Peppermint oil may also be used topically as a chest rub for coughs and asthma. The oil will help ease breathing through relaxing the smooth muscles of the bronchioles.

Even though the use of peppermint can be quite safe, allergic reactions have been experienced. The most common reaction is contact dermatitis, although other signs such as bradycardia and muscle tremors have been noted. These reactions have a higher incidence of occurrence if the oil is used in conjunction with a heating pad.

The use of M. piperita oil for infants and young children may be contraindicated because of an increased risk of choking due to laryngeal spasms. Use by individuals with a predisposition to heartburn and LES reflux is also contraindicated because the oil will most likely worsen the condition. Even though in most cases M. piperita is safe to use, the volatile oil can be quite toxic. Consult a practitioner before use.

Please Note: The information contained in this section of the web site is directed toward people with technical knowledge in the botanical medicine field. We provide this information as a service to naturopathic physicians, pharmacognocists, pharmacists, midwives, plant chemists and medical herbalists and we encourage health professionals to obtain a more general education in the area before applying treatments to themselves or their patients. Bastyr University assumes no responsibility for the results obtained from using this information. If you have a serious or lingering health concern, it is important to discuss it with a health care provider.