Peppermint is a flowering plant that grows throughout Europe and North America. Peppermint is widely cultivated for its fragrant oil. Peppermint oil has been used historically for numerous health conditions, including common cold symptoms, cramps, headache, indigestion, joint pain, and nausea. Peppermint leaf has been used for stomach/intestinal disorders and for gallbladder disease.

Mint plants such as peppermint and spearmint have a long history of medicinal use, dating to ancient Egypt, Greece, and Rome. The scientific name for peppermint ( Mentha x piperita ) is derived from the name  Mintha , a Greek mythological nymph who transformed herself into the plant, and from the Latin  piper  meaning "pepper." Peppermint is believed to be a cross (hybrid) between spearmint and water mint.

Peppermint oil is available in bulk herb oil, enteric-coated capsules, soft gelatin capsules, and in liquid form. In small doses such as in tea or chewing gum, peppermint is generally believed to be safe in healthy, non-pregnant, non-allergic adults. The United States is a principal producer of peppermint, and the largest markets for peppermint oil are manufacturers of chewing gum, toothpaste, mouthwash, and pharmaceuticals.

Balm mint, black peppermint, brandy mint, curled mint, Feullis de menthe, Japanese peppermint, Katzenkraut (German), lamb mint,  Mentha arvensis  L. var piperascens, menta prima (Italian),  Menthae piperitae  aetheroleum (peppermint oil),  Menthae piperita  var officinalis,  Menthae piperitae  folium (peppermint leaf),  Menthe anglaise ,  Menthe poivre ,  Menthe poivree ,  Mentha piperita  var vulgaris, Our Lady's mint, pebermynte (Danish), peppermint oil, Pfefferminz (German), Porminzen, Schmecker, spearmint ( Mentha spicata  L.), water mint ( Mentha aquatica ), white peppermint, WS(R) 1340.

Note:  Mentha x villosa  L. is a different species of mint with a similar appearance, used primarily as a flavoring agent.

*Key to grades

A: Strong scientific evidence for this use;

B: Good scientific evidence for this use;

C: Unclear scientific evidence for this use;

D: Fair scientific evidence against this use;

F: Strong scientific evidence against this use.

Grading rationale

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Adults (18 years and older)

Peppermint oil should be used cautiously, as doses of the constituent menthol over 1 gram per kilogram of body weight may be deadly. For intestinal/digestion disorders, doses of 0.2 to 0.4 milliliters of peppermint oil in enteric-coated capsules, dilute preparations, or suspensions taken three times daily by mouth have been used or studied. Lozenges containing 2 to 10 milligrams of peppermint oil have been used. 10% peppermint oil (in methanol) has been applied to the skin (forehead and temples) multiple times per day for headache relief. Some sources recommend using peppermint oil preparations on the skin no more than 3 to 4 times per day. For inhalation, 3 to 4 drops of oil added to 150 milliliters of hot water and inhaled up to three times per day or 1% to 5% essential oil as a nasal ointment has been used to relieve congestion.

As an infusion, 3 to 6 grams of peppermint leaf has been used daily. Doses of other liquid preparations depend on concentration, for example, 2 to 3 milliliters of tincture (1:5 in 45% ethanol) three times daily, or 1 milliliter of spirits (10% oil and 1% leaf extract, mixed with water) has been taken. Various doses of dried herb extract have also been used, ranging from 0.8 gram daily up to 4 grams taken three times daily, although safety is not clear.

Children (younger than 18 years)

There is not enough scientific information available to recommend the safe use of peppermint leaf or oil in children.

Allergies

Allergic/hypersensitivity reactions may occur from using peppermint or menthol by mouth or on the skin, including throat closing (laryngeal spasm), breathing problems (bronchial constriction/asthma symptoms), or skin rash/hives/contact dermatitis. People with known allergy/hypersensitivity to peppermint leaf or oil should avoid peppermint products.