Mentha x piperita
Composition: The therapeutic effects of peppermint are primarily derived from the composition of its essential oil—menthol and menthone, though its flavonoids and tannins also have pharmacologic actions.
Description and History: Steam distilled peppermint oil is clear and thin with a strong minty scent. The aroma is concentrated, and much deeper than that of spearmint. It is a top note in perfumery. Peppermint is produced in the US and China for the production of menthol. Most US oils are actually blends of assorted regional oils. For aromatherapy uses, the oils from England and France are the most desirable, since they are produced for this exact purpose.
Pharmacological Actions: Peppermint is cooling, acts as an antigalactogogue, has antitussive abilities, and is a calming, based upon the scientific literature.
Cross-Reference List: Cough; Headache; Nausea & Vomiting; Cold Sores
Antimicrobial: Peppermint oil was evaluated for its antiviral activity against herpes type 1 and 2 in a 2003 in vitro study. It was tested against drug-resistant strains, which are increasingly common and present difficulties in treatment. The oil profile was consistent with a typical peppermint oil sourced from the US or the UK. In this study, it was found to be effective for both types within a 2-3 hour period. What is significant about this study is that the pharmaceutical product used for comparison inhibits viral replication inside the cell, whereas peppermint oil was found to inhibit it before it enters the cell. Viruses are not technically living things and can only replicate inside of a cell, so the ability to render it inactive before it enters the cell is extremely promising when it comes to treating resistant infections.
Intestinal Complaints: The use of peppermint oil with the greatest amount of scientific evidence is the internal consumption of the capsules for intestinal complaints, specifically irritable bowel syndrome (IBS). In addition to conclusive studies on the subject, there are a couple of pharmaceutical products available by prescription in certain European countries that contain peppermint oil for the clinical treatment of IBS.
A 2005 literature review published in the journal Phytomedicine discusses the results of 16 studies on the use of peppermint oil, specifically with irritable bowel syndrome, which met inclusion criteria. Ten of the studies were randomized and twelve were placebo-controlled. Three studies compared the use of peppermint oil with pharmaceutical alternatives. While many of the studies were small in size, the total of all 16 studies represents 661 total trial patients. The range of success with the treatment was 39% to 79%, and adverse events included heartburn and anal burning. However, the pharmaceutical alternative also resulted in adverse events, and the overall conclusion from this review is that peppermint oil is a safe and effective treatment for IBS. In these studies, the dosage ranged in size and the supplement was enteric coated in 15 of the 16 studies.
Enteric coating provides a protective layer that enables the supplement to avoid being broken down in the harsh acidic environment of the stomach. This cannot be replicated at home in gelcaps or through chewables or similar products. Therefore, the applications of these studies are limited in scope due to the inability to replicate the products specifically in a home environment. However, traditional use also supports the consumption of peppermint products as an herbal remedy for digestive complaints, so the use of an after-dinner mint or similar preparation may have some additional benefits beyond simply freshening the breath. To evaluate the specifics of non-enteric coated alternatives, further studies are needed.
Gastric Spasms: Tested during upper endoscopy, the patients who had been given peppermint oil internally had a significant reduction in overall gastric spasms compared to the control group. (Kurosaka, et al, 2003) Currently, an anti-spasmodic injection is given to patients undergoing this procedure, and it carries significant side effects. With this success, the study concludes that peppermint oil is preferable thanks to its efficacy and safety in reducing gastric spasms.
Fatigue: Inhalation of oil reduces burnout or fatigue, according to results from a study group in 2013. During the study, patients inhaled peppermint oil for 3x each day over the course of one week, Monday through Friday. Participants self-reported significantly reduced feelings of fatigue and burnout as compared to the control group. (Varney & Buckle, 2013).
It should be noted that inhalation has some mixed reviews. One study that compared peppermint EO inhalation to placebo and alcohol wipes found no statistical difference proposes that inhalation is inconsistent in some individuals. (Anderson & Gross, 2004) If inhalation alone doesn’t work for you, other treatments may be needed alongside it in order to improve results.
Contraindications: The oil should not be applied to the face or chest of babies or young children. The oil should not be used consumed during lactation as it has the potential to dry up the milk supply and should not be consumed in medicinal amounts by children 12 and younger without training in aromatic medicine.
Interactions: The topical use of peppermint oil can enhance the penetration of other substances. The internal use of the oil can slow the absorption of other drugs. Peppermint tea has been shown to reduce the absorption of iron supplementation. Peppermint can lower esophageal sphincter pressure, so care should be taken with GERD.
Optimal Preparations: The topical use of peppermint oil can enhance the penetration of other substances. For internal use, it can be ingested in culinary preparations in small amounts and used for environmental purposes in cleaning supplies or room sprays.
Dose: For internal medicinal actions, the dose of peppermint EO ranges from 3-9 drops/day, depending upon purpose and function, indefinitely. For topical applications, the EO can be used in a preparation of 10% with the total application not exceeding 1-2 drops, up to 4-5x per day, indefinitely. Stronger preparations can be used short-term with training in aromatherapy.
Anderson, L. A., & Gross, J. B. (2004). Aromatherapy with peppermint, isopropyl alcohol, or placebo is equally effective in relieving postoperative nausea. Journal of PeriAnesthesia Nursing, 19(1), 29-35.
Grigoleit, H-G., Grigoleit, P., (2005). Review: Peppermint oil in irritable bowel syndrome. Phytomedicine. 12: 601-606.
Hiki, N., Kurosaka, H., Tatsutomi, Y., Shimoyama, S., Tsuji, E., Kojima, J., ... & Mafune, K. I. (2003). Peppermint oil reduces gastric spasm during upper endoscopy: a randomized, double-blind, double-dummy controlled trial. Gastrointestinal endoscopy, 57(4), 475-482.
Schuhmacher, A., Reichling, J., & Schnitzler, P., (2003). Virucidal effect of peppermint oil on the enveloped viruses herpes simplex virus type 1 and type 2 in vitro. Phytomedicine, 10: 504-510.
Varney, E., & Buckle, J. (2013). Effect of inhaled essential oils on mental exhaustion and moderate burnout: a small pilot study. The Journal of Alternative and Complementary Medicine, 19(1), 69-71.
Meet Dr Hawkins
Dr. Hawkins brings 20 years of expertise in the integrative health field to her role as Executive Director of the Franklin School of Integrative Health Sciences and the leader of our clinical research team.
She holds a Bachelor’s Degree in Environmental Health from Union Institute and University, a Master’s Degree in Health Education & Promotion from the University of Alabama, a post-graduate certificate in epidemiology from the London School of Hygiene and Tropical Medicine, a PhD in Health Research from Middle Tennessee State University, and is completing the post-doctoral Global Scholars Research Training Program at Harvard Medical School. She also holds certifications in numerous natural health fields including aromatherapy, aromatic medicine, herbalism, childbirth education, and labor support.