Michael Malone is with the Department of Family and Community Medicine at the Penn State College of Medicine in Hershey, Pennsylvania. Gary Tsai is with Torrance Memorial Physician Network in California.
The authors reported no potential conflict of interest relevant to this article, which originally appeared in The Journal of Family Practice (2018;67[1]:10-16).
Mentha piperita, also known as peppermint, is a hybrid between water mint and spearmint. It is found throughout Europe and North America and is commonly used in tea and toothpaste and as a flavoring for gum. Menthol and methyl salicylate are the main active ingredients in peppermint, and peppermint has calcium channel–blocker effects.39 Menthol has been shown to help regulate cold and pain sensation through the TRPM8 receptor.40 The peppermint herb is used both orally and topically, and has been studied in the treatment of multiple conditions.
Irritable bowel syndrome (IBS). It appears that peppermint inhibits spontaneous peristaltic activity, which reduces gastric emptying, decreases basal tone in the gastrointestinal tract, and slows down peristalsis in the gut.39
The American College of Gastroenterology guidelines currently note that there is moderate-quality evidence for peppermint oil in the treatment of IBS.41 A Cochrane review concluded that peppermint appears to be beneficial for IBS-related symptoms and pain.42 In a systematic review of nine studies from 2014, peppermint oil was found to be more effective than placebo for IBS symptoms such as pain, bloating, gas, and diarrhea.43 The review also indicated that peppermint oil is safe, with heartburn being the most common complaint.43 A 2016 study also found that triple-coated microspheres containing peppermint oil reduced the frequency and intensity of IBS symptoms.44
Non-ulcer dyspepsia. In combination with caraway oil, peppermint oil can be used to reduce symptoms of non-ulcer dyspepsia.45,46 A multicenter, randomized, placebo-controlled, double-blind study found that 43.3% of subjects improved with a peppermint-caraway oil combination after eight weeks, compared with 3.5% receiving placebo.46
Barium enema–related colonic spasm. Peppermint can relax the lower esophageal sphincter, and it has been shown to be useful as an antispasmodic agent for barium enema–related colonic spasm.47,48
Itching/skin irritation. Peppermint, when applied topically, has been used to calm pruritus and relieve irritation and inflammation. It has a soothing and cooling effect on the skin. At least one study found it to be effective in the treatment of pruritus gravidarum, although the study population consisted of only 96 subjects.49
Migraine headache. Initial small trials suggest that menthol is likely beneficial for migraine headaches. A pilot trial of 25 patients treated with topical menthol 6% gel for an acute migraine attack showed a significant improvement in headache intensity two hours after gel application.50 In a randomized, triple-blind, placebo-controlled, crossover study of 35 patients, a menthol 10% solution was shown to be more efficacious as abortive treatment of migraine headaches than placebo.51
Tension headache. In a randomized, placebo-controlled, double-blind crossover study, topical peppermint oil showed a significant clinical reduction in tension headache pain.52 Another small, randomized, double-blind trial showed that tiger balm (containing menthol as the main ingredient) also produced statistically significant improvement in tension headache discomfort compared with placebo.53
