Peppermint (Mentha piperita), a popular flavoring for gum, toothpaste, and tea, is also used to soothe an upset stomach or to aid digestion. Because it has a calming and numbing effect, it has been used to treat headaches, skin irritations, anxiety associated with depression, nausea, diarrhea, menstrual cramps, and flatulence. It is also an ingredient in chest rubs, used to treat symptoms of the common cold. In test tubes, peppermint kills some types of bacteria, fungus, and viruses, suggesting it may have antibacterial, antifungal, and antiviral properties. Several studies support the use of peppermint for indigestion and irritable bowel syndrome.
Peppermint 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. However, if your symptoms of indigestion are related to a condition called gastroesophageal reflux disease or GERD, you should not use peppermint (see "Precautions" section).
Peppermint relaxes the muscles that allow painful digestive gas to pass.
Irritable Bowel Syndrome (IBS)
Several studies have shown that enteric coated peppermint capsules can help treat symptoms of IBS, such as pain, bloating, gas, and diarrhea. (Enteric coated capsules keep peppermint oil from being released in the stomach, which can cause heartburn and indigestion.) However, a few studies have shown no effect. One study examined 57 people with IBS who received either enteric coated peppermint capsules or placebo twice a day for 4 weeks. Of the people who took peppermint, 75% had a significant reduction of IBS symptoms. Another study comparing enteric coated peppermint oil capsules to placebo in children with IBS found that after 2 weeks, 75% of those treated had reduced symptoms. Finally, a more recent study conducted in Taiwan found that patients who took an enteric coated peppermint oil formulation 3 - 4 times daily for one month had less abdominal distention, stool frequency, and flatulence than those who took a placebo. Nearly 80% of the patients who took peppermint also had alleviation of abdominal pain.
Itching and Skin Irritations
Peppermint, when applied topically, has a soothing and cooling effect on skin irritations caused by hives, poison ivy, or poison oak.
One small study suggested that peppermint applied to the forehead and temples helped reduce headache symptoms.
Colds and Flu
Peppermint and its main active agent, menthol, are effective decongestants. Because menthol thins mucus, it is also a good expectorant, meaning that it helps loosen phlegm and breaks up coughs. It is soothing and calming for sore throats (pharyngitis) and dry coughs as well.
Peppermint plants grow to about 2 - 3 feet tall. They bloom from July through August, sprouting tiny purple flowers in whorls and terminal spikes. Dark green, fragrant leaves grow opposite white flowers. Peppermint is native to Europe and Asia, is naturalized to North America, and grows wild in moist, temperate areas. Some varieties are indigenous to South Africa, South America, and Australia.
What's It Made Of?
The leaves and stems, which contain menthol (a volatile oil), are used medicinally, as a flavoring in food, and in cosmetics (for fragrance).
Peppermint tea is prepared from dried leaves of the plant and is widely available commercially.
Peppermint spirit (tincture) contains 10% peppermint oil and 1% peppermint leaf extract in an alcohol solution. A tincture can be prepared by adding 1 part peppermint oil to 9 parts pure grain alcohol.
Enteric coated capsules 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 - 16% menthol)
How to Take It
Do not give peppermint to an infant or small child. Peppermint oil applied to the face of infants can cause life-threatening breathing problems. In addition, peppermint tea may cause a burning sensation in the mouth. For digestion and upset stomach in older children: 1 - 2 mL peppermint glycerite per day.
The use of herbs is a time honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.
Do not take peppermint or drink peppermint tea if you have gastroesophageal reflux disease (GERD -- a condition where stomach acids back up into the esophagus) or hiatal hernia. Peppermint can relax the sphincter between the stomach and esophagus, allowing stomach acids to flow back into the esophagus. (The sphincter is the muscle that separates the esophagus from the stomach.) By relaxing the sphincter, peppermint may actually make the symptoms of heartburn and indigestion worse.
Peppermint, in amounts normally found in food, is likely to be safe during pregnancy, but not enough is known about the effects of larger supplemental amounts. Speak with your health care provider.
Never apply peppermint oil to the face of an infant or small child, as it may cause spasms that inhibit breathing.
Peppermint may make gallstones worse.
Large doses of peppermint oil can be toxic. Pure menthol is poisonous and should never be taken internally. It is important not to confuse oil and tincture preparations.
Menthol or peppermint oil applied to the skin can cause a rash.
Cyclosporine -- This drug, which is usually taken to prevent rejection of a transplanted organ, suppresses the immune system. Peppermint oil may slow down the rate at which the body breaks down cyclosporine, meaning more of it stays in your bloodstream. Do not take peppermint oil if you take cyclosporine.
Drugs that reduce stomach acid -- If peppermint capsules are taken at the same time as drugs that lower the amount of stomach acid, the enteric-coated peppermint capsules may dissolve in the stomach instead of the intestines. This could mean the effects of peppermint are lessened. Take peppermint at least 2 hours before or after an acid-reducing drug. Antacids include:
Drugs that treat diabetes -- Test tube studies suggest peppermint may lower blood sugar, raising the risk of hypoglycemia (low blood sugar).
Medications changed by the liver -- Since peppermint works on the liver, it may affect medications that are metabolized by the liver (of which there are many). Speak with your health care provider.
Antihypertensive drugs (blood pressure medications) -- Some animal studies suggest that peppermint may lower blood pressure. If you take medications to lower blood pressure, taking peppermint also might make their effect stronger.
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Review Date: 4/3/2011
Reviewed By: Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.
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