The Effect of Peppermint (Mentha piperita) Extract on the Severity of Nausea, Vomiting and Anorexia in Patients with Breast Cancer Undergoing Chemotherapy: A Randomized Controlled Trial.

Background and Objective: Nausea, vomiting, and anorexia are the most common side effects reported in cancer patients undergoing chemotherapy. The present study aimed to determine the effect of peppermint extract on the severity of nausea, vomiting, and anorexia in patients with breast cancer undergoing chemotherapy. Methods and Materials: In this randomized controlled trial, we selected 84 patients with breast cancer undergoing chemotherapy. They were then assigned to 2 groups of experimental and control (n = 42, each) using block randomization. Patients in the experimental group received 40 drops of peppermint extract mixed in 20 cc of tap water every 8 hours, while patients in the control group received 40 drops of distilled water mixed in 20 cc of tap water every 8 hours. The severity of nausea, vomiting, and anorexia was measured and recorded before the intervention, and immediately, 24 and 48 hours after the chemotherapy using the Visual Analogue Scale. Statistical analysis of the data was conducted using SPSS software version 21. Results: The results of the present study revealed that there was a significant difference between the 2 groups at 24 and 48 hours after the chemotherapy (P < .05), so that the mean score of the severity of nausea, vomiting, and anorexia in the experimental group was lower than in the control group (P < .05). Conclusion: The use of peppermint as a method in complementary medicine may improve nausea, vomiting, and anorexia in patients with breast cancer undergoing chemotherapy. Further studies with greater sample size and longer follow-up period are needed to confirm the current findings.