Peppermint is helpful for many stomach ailments and promotes good digestion. Because it has a calming and numbing effect, it is useful for headaches and skin irritations, and may aid in the treatment of anxiety associated with depression. It also relieves many symptoms of colds and flu.

Peppermint is helpful for nausea, diarrhea, indigestion, morning sickness, and flatulence. It calms the muscles of the stomach and improves the flow of bile, which the body uses to digest fats. As a result, food passes through the stomach more quickly, which helps many digestive problems. Peppermint also relaxes the muscles that allow the body to rid itself of painful digestive gas.

These are some of the other conditions that may be improved by peppermint:

• Menstrual cramps—Because peppermint is effective for relaxing muscles, it is very helpful for painful cramps.
• Irritable bowel syndrome—Research has shown that enteric-coated peppermint capsules are able to calm and soothe intestinal muscles. This provides pain relief and healing for this common stress-related syndrome.
• Gallstones—Peppermint oil can help the body break down gallstones, providing a safe alternative to surgery.
• Viruses—Peppermint oil has exhibited antiviral properties and may be helpful in the treatment of some viral conditions such as flu, mumps, sinusitis, sore throats, cold sores, and genital sores caused by herpes.
• Itching and skin irritations—Peppermint has a soothing and cooling effect on skin irritations caused by hives, poison ivy, or poison oak.
• Tension headaches and migraines—Research has shown that peppermint oil's ability to relax muscles and relieve pain has made it particularly effective against headache pain.
• Colds and flu—Peppermint and its main active agent, menthol, are effective decongestants. Because menthol thins mucus, it is also a good expectorant. It is soothing and calming for sore throats and dry coughs as well.

Peppermint plants have square stems, and can grow up to two feet tall. They bloom from July through August, sprouting tiny purple flowers in whorls and terminal spikes. Simple, toothed, and fragrant leaves grow opposite the flowers. Peppermint is native to Europe and Asia, and some varieties are indigenous to South Africa, South America, and Australia. It is naturalized in North America and cultivated in Oregon, Washington, and Wisconsin.

Peppermint preparations start with the leaves and flowering tops of the plant. These contain a volatile oil, where you find peppermint's primary active component, menthol.

Peppermint may be dried from fresh peppermint leaves, and is also widely available as tea.

Tinctures—Peppermint spirit is an alcoholic solution containing 10% peppermint oil and 1% peppermint leaf extract. To make your own tincture, add 1 part peppermint oil to 9 parts pure grain alcohol.

Enteric-coated capsules, which are specially coated to allow the capsule to pass through the stomach and into the intestine (0.2 ml of peppermint oil per capsule)

Creams or ointments (should contain 1 to 16 percent menthol)

Pediatric

• For digestion and upset stomach: 1 to 2 mL peppermint glycerite daily.

Adult

You can make peppermint tea (infusion) with 1 to 2 tsp of dried leaves per 8 oz of hot water. To aid digestion or to soothe an upset stomach, drink 3 to 4 cups of peppermint tea daily. For vomiting, take 3 to 6 g of leaf, or 5 to 15 drops of tincture.

• Irritable bowel syndrome—Take 1 to 2 coated capsules three times daily between meals.
• Gallstones—Take 1 to 2 enteric-coated capsules three times daily between meals.
• Itching and skin irritations—Apply menthol, the active ingredient in peppermint, in a cream or ointment form no more than three to four times daily.
• Tension headaches and migraines—Several studies have suggested that applying a tincture of peppermint oil to the forehead may be as effective as taking two acetaminophen tablets. Lightly coat the forehead and allow the tincture to evaporate.

Peppermint tea is generally safe, but pregnant or nursing mothers should drink only small amounts of peppermint tea. Those with a history of miscarriage should not use peppermint while pregnant.

Rare negative reactions to enteric-coated peppermint oil capsules may include skin rash, heartburn, slow heart rate, and muscle tremors.

Menthol or peppermint oil applied to the skin could cause contact dermatitis or rash. Peppermint oil should be diluted and taken in small amounts, since large doses could cause kidney damage. Pure menthol is poisonous and should never be taken internally. Peppermint oil and menthol should not be applied to the faces of infants and small children. Be careful not to confuse oil and tincture preparations.

In an animal study, topical peppermint oil increased the absorption of 5-fluorouracil, a medication used to treat cancer that was also applied topically. It is too early to draw conclusions about the usefulness of these findings to humans. Therefore, it would be wise to avoid applying peppermint oil topically when using other topical medications.

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