One of the world’s oldest medicinal herbs, peppermint has been used medicinally and for culinary purposes for centuries in both Eastern and Western traditions, and is also a common addition to food and cosmetic products. The leaf, usually as an infusion or tincture, and the volatile oil are both widely useds, especially for disorders of the digestive system. The benefits of peppermint oil in the treatment of irritable bowel syndrome are quite well-supported by clinical trials. It has also been shown to relieve non ulcer dyspepsia, nausea, and spastic conditions of the gallbladder and bile ducts. Inhaled, peppermint oil (due to its menthol component) can help to ease the symptoms of coughs and colds, and applied topically may relieve neuralgia, pruritus and headaches. Although using the whole herb is generally free of adverse reactions in those without a particular sensitivity, peppermint oil can cause heartburn or perianal discomfort, and should be avoided in patients with obstructive bile duct problems, severe liver damage and oesophageal reflux. The oil should also be used with caution in children and may cause adverse neurological symptoms in excessively high doses in rare cases.