Modern Use & Current Research



               Many of the traditional uses of peppermint are still being used today, especially those to treat symptoms of the GI tract. In particular, peppermint oil is commonly used to treat digestive problems, heartburn, nausea, abdominal pains, headache, and coughs (Sustrikova & Salamon, 2004). Irritable bowel syndrome (IBS) is a relatively common condition characterized by abdominal distension and pain, bloating, flatulence, and diarrhoea. Due to the success of peppermint oil in treating traditional GI tract ailments, many recent studies have been conducted to test its efficacy in treating IBS. Cappello et al. (2007) published a study in which a double-blind placebo-controlled randomized trial was performed on fifty-seven patients with IBS ranging in age from 18 to 80 years old. Both the peppermint oil and placebo were prepared in enteric-coated capsules, containing 225mg of their respective substances, two of which were given randomly to each patient twice a day for 4 weeks. At the end of the trial, it was found that the number of patients in the peppermint oil group that had a greater than 50% reduction in total IBS symptoms were significantly larger than in the placebo group (Figure 1) (Cappello et al., 2007).

(Cappello et al., 2007)

               This finding illustrates that treating IBS patients with two enteric-coated capsules of peppermint oil twice a day for 4 weeks will significantly reduce symptoms of IBS for approximately 1 month after treatment (Cappello et al., 2007). The protocol of the study was sound in that a double-blind RCT was conducted using standardized doses of the treatments. Furthermore, the authors ensured an appropriate balance of baseline conditions between the patients in the two groups.

               Migraines affect many people all over the world and can be quite disabling when severe. Haghighi et al. (2010) conducted a study on the efficacy of peppermint oil, with particular focus on its menthol component, on the treatment of migraine without aura. A triple-blind placebo-controlled randomized trial was performed on 60 patients experiencing migraines ranging in age from 18 to 65 years old. The peppermint drug was prepared by mixing 10% menthol crystals in ethanol. One ml of either the drug or the placebo was applied twice on the forehead and temporal area with a 30 minute interval between each application and left untouched for 2 hours. At the end of the trial, it was found that 38.3% of patients in the drug group and 12.1% of patients in the placebo group were “pain free” 2 hours after treatment (Haghighi et al., 2010). Furthermore, 33.3% of the drug group and 12.1% of the placebo group maintained a pain free response during the first 24 hours after treatment (Figure 2) (Haghighi et al., 2010).

(Haghighi et al., 2010)

               The findings of this study indicate that the application of a 10% solution of menthol and ethanol is statistically significant in the treatment of migraines (Haghighi et al., 2010). The protocol of this study is sound in that a triple-blind RCT was conducted, but the solution of menthol in ethanol may have not been adequate enough to produce more favourable results.