Also known as M. piperita.
Peppermint is widely cultivated, particularly within Europe and the USA. It has quadrangular stems, and leaves up to 9cm long and 3cm broad. The flowers are small, lilac, or reddish-purple, with a characteristic taste and odour.
Peppermint contains essential oil (up to 1.5%) containing menthol, and flavonoids, along with other minor constituents such as choline and carotenes. It is used as a spasmolytic, carminative and diaphoretic, and has powerful antiviral and antiseptic properties.
Peppermint oil is often used in many indigestion and stomach mixtures (as it reduces the symptoms of colic, flatulence and diarrhoea), and the herb is used in herbal teas. Peppermint is used for its anti-emetic properties (prevents vomiting), and for promoting the flow of bile from the liver. It is also used in some cough and cold remedies; menthol being used in a similar way for oral ingestion and inhalation. Applied in the form of a balm or oil, it is thought to be effective against tension headaches, and is a popular treatment for this in the Far East.
Peppermint is also widely used as a popular flavouring for sauces, liqueurs, sweets, toothpastes, mouthwashes and medicines.