Peppermint Oil Introduction

Peppermint, or varieties of the modern plant, has been used medicinally since the heydays of the Greeks and Romans, who used the plant’s essence in cooking, wine and as a medicinal remedy. Prior to their time, the Egyptians cultivated peppermint and it was later mentioned in the Icelandic pharmacopoeia in the thirteenth century. Peppermint did not become part of the medicinal compendium in modern times until it was reintroduced in Western Europe in the mid-eighteenth century.

Early herbal medicine texts mention peppermint as a good remedy for ‘raising internal heat and inducing perspiration’, and was recommended as an early treatment for colds to affect a cure. Peppermint is known as a stomachic (aids and improves the action of the stomach) and as a carminative, which is typically defined as a plant rich in aromatic volatile oils that assists in proper digestive tract function, soothing the gut, decreasing inflammatory conditions, and helps with expelling gas from the digestive tract. Having these actions, peppermint is most suited for certain types of indigestion, typically flatulence and colic. It is also useful for treating sharp cramping pains beneath the diaphragm. Apart from the leaves of the plant, peppermint oil is the most widely used volatile oil in medicine and other commercial purposes. Peppermint oil exerts the strongest anti-spasmodic action of any other volatile oil, and is widely used in medicines for this purpose.

Peppermint Oil Food Sources

Parts Used

The aerial parts of the peppermint plant are used when using the herb, while the oil is produced by steam distillation of fresh, flowering peppermint.[1] Peppermint leaves contain many active compounds, the chief ones being menthol, hesperidin, diosmin, and rosmarinic acid. Peppermint oil is typically comprised of 28% menthol, 20-30% menthone, and 3-10% menthyl acetate.[2] Higher quality oils often have even higher amounts of menthol in them, approaching 44%.

Peppermint Oil Uses

Peppermint leaf has several indications, many of them involving gastrointestinal (GI) tract ailments. Among these are gastritis, flatulence, nausea and vomiting, loss of appetite, and spasms of the GI tract including the gallbladder and bile ducts.[3] Other ‘above the belly’ uses include treatment of the common cold, bronchitis, sinusitis, fever and cough. Peppermint may also be useful in treating painful menses (cramping) and for morning sickness-associated nausea.

Newer research demonstrates a possible role of peppermint in treating symptoms of allergic rhinitis, or hay fever. Although this particular study was performed using laboratory animals, peppermint appeared to significantly decrease allergic symptoms; application of these results in human subjects is yet to be determined.[4]

Meanwhile, peppermint oil is more widely used for treatment of medical conditions. Peppermint oil can be used internally for many of the above-mentioned symptoms, yet must be specifically dosed in order to avoid toxicity. Applied topically, it is useful for treating headaches, muscle pain, toothaches, and joint pain and as a mosquito repellent. Perhaps the most applicable use of the oil is its use as an aromatic treatment for cough and cold symptoms, and has been used for treating pain when inhaled.

Peppermint oil is especially proven in relieving GI spasms; this is documented in several different studies and the oil was mixed in a solution with another volatile oil (caraway oil).[5-7] For tension headaches, peppermint oil applied topically across the forehead and temple regions and its efficacy was shown to be comparable to 1000 milligrams of acetaminophen for pain relief.[8]

Peppermint Oil Dosages

Peppermint leaf is typically dosed as an infusion, otherwise known as a tea. Standard dosing is 2 to 3 grams of fresh leaf added to infusions, two to three times per day. Peppermint dosed in this way is typically used for less severe complaints, while the oil may be dosed (for adults) at roughly 0.2 to 0.4 milliliters of oil, three times per day. Caution must be used when taking volatile oils internally as there is a relatively high risk of overdosage due to the concentrated nature of the oil. For purposes of inhalation, 2 to 3 drops of the oil in a steaming apparatus is sufficient.

Peppermint Oil Toxicities and Contraindications

Side effects

Peppermint Leaf: There is some speculation that large amounts of peppermint leaf may negatively affect male libido by lowering testosterone levels.[9] This study was performed on laboratory animals and cannot be extrapolated directly to humans; however some anecdotal evidence exists suggesting that more than 4 cups of peppermint leaf tea in a day may decrease libido.

Peppermint Oil: Peppermint oil may cause heartburn, allergic reactions and nausea and vomiting; this is why peppermint oil is typically available in enteric-coated capsules.[10]

General interactions (supplement, herb, food, lab)

Peppermint Leaf: There are no known interactions with other herbs, supplements or foods. As mentioned previously, peppermint may lower testosterone levels in male animals and if this occurs in humans, then testosterone laboratory levels will be lower. Similarly, this original study noted alterations in follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the study animals. This may occur in humans as well but this is unknown at this time.

Peppermint Oil: Enterically coated peppermint oil capsules may prematurely dissolve in the gut when taken with food, due to the accompanying increase in acid production; therefore they should be taken at least 2 hours away from meals.[11]

Drug interactions

Peppermint Leaf: There is some evidence that peppermint leaf may inhibit certain liver enzymes that are responsible for metabolizing specific types of drugs; this evidence has not been shown in humans but lab animals.[12]

Peppermint Oil: Similarly, peppermint oil may inhibit several different types of liver enzymes that are responsible for regulating drug metabolism; this can lead to increased levels of drugs in the body.[13, 14] Antacid medications may lead to premature dissolution of enteric-coated capsules leading to GI upset.[11]Similarly, drugs that are meant to decrease stomach acid (H2-Blockers and Proton pump inhibitors) may cause premature dissolution of the capsules.

Disease conditions

Peppermint Leaf: Peppermint leaf has not been shown to interfere with any disease conditions.

Peppermint Oil: The oil may worsen gastroesophageal reflux disease (GERD) because of peppermint’s effect on relaxing muscles surrounding the stomach and other areas in the GI tract. [15]


1. Blumenthal M, Goldberg A, Brinckmann J, eds. Herbal Medicine Expanded Commission E Monographs. Newton, MA: Integrative Medicine Communications, 2000.

2. Pizzorno JE, Murray MT, eds. Textbook of Natural Medicine. 2nd ed. New York, NY: Chuchill Livingstone, 1999.

3. Online document at:

4. Inoue T, Sugimoto Y, Masuda H, Kamei C. Effects of peppermint (Mentha piperita L.) extracts on experimental allergic rhinitis in rats. Biol Pharm Bull 2001;24:92-5.

5. Madisch A, Heydenreich CJ, Wieland V, et al. Treatment of functional dyspepsia with a fixed peppermint oil and caraway oil combination preparation as compared to cisapride. A multicenter, reference-controlled, double-blind equivalence study. Arzneimittelforschung 1999;49:925-32.

6. May B, Kuntz HD, Kieser M, Kohler S. Efficacy of a fixed peppermint oil/caraway oil combination in non-ulcer dyspepsia. Arzneimittelforschung 1996;46:1149-53.

7. May B, Kohler S, Schneider B. Efficacy and tolerability of a fixed combination of peppermint oil and caraway oil in patients suffering from functional dyspepsia. Aliment Pharmacol Ther 2000;14:1671-7.

8. Gobel H, Fresenius J, Heinze A, et al. [Effectiveness of Oleum menthae piperitae and paracetamol in therapy of headache of the tension type]. [Article in German]. Nervenarzt 1996;67:672-81.

9. Akdogan M, Ozguner M, Kocak A, et al. Effects of peppermint teas on plasma testosterone, follicle-stimulating hormone, and luteinizing hormone levels and testicular tissue in rats. Urology 2004;64:394-8.

10. Kline RM, Kline JJ, Di Palma J, Barbero GJ. Enteric-coated, pH-dependent peppermint oil capsules for the treatment of irritable bowel syndrome in children. J Pediatr 2001;138:125-8.

11. Foster S. Peppermint, Menta x piperita, botanical series #306. Austin, TX: Am Botanical Council, 1990.

12. Maliakal PP, Wanwimolruk S. Effect of herbal teas on hepatic drug metabolizing enzymes in rats. J Pharm Pharmacol 2001;53:1323-9.

13. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;18:2273-81.

14. Dresser GK, Wacher V, Wong S, et al. Evaluation of peppermint oil and ascorbyl palmitate as inhibitors of cytochrome P4503A4 activity in vitro and in vivo. Clin Pharmacol Ther 2002;72:247-55. 11 Ibid

15. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.


Peppermint Oil (Mentha
piperita) (leaf) Products