The effect of peppermint (Mentha piperita) capsules on the severity of primary dysmenorrhea

Background and objectivesPrimary dysmenorrhea refers to painful menstrual cramps without an organic cause and is one of the most common problems for women during reproductive ages. Given the high prevalence of primary dysmenorrhea and its undesirable effects on the quality of life, and also given the evidence on the analgesic properties of peppermint capsules, the present study was conducted to investigate the effect of these capsules on the severity of primary dysmenorrhea in female students living in the dormitories of North Khorasan University of Shirvan, Iran in 2014–2015.Materials and methodThis double-blind clinical trial was conducted on 102 eligible female students (aged 18–25) living in the dormitories of North Khorasan University of Shirvan from August 2014 to February 2015. The study subjects were initially matched in terms of the reported severity of primary dysmenorrhea and then divided into a peppermint capsule group (46 students) and a placebo group (44 students). The treatment group received three 330 mg peppermint capsules per day, and the placebo group received three identical placebo capsules containing starch, which were taken from the first to the third day of their menstrual cycle with identical administrations. The severity of pain was measured and compared before the intervention and over two successive cycles based on a visual analogue scale (0–10 cm). The data obtained was analyzed in SPSS-17 using the independent t-test and the ANOVA at the significance level of P < 0.05 .ResultsNo significant differences were observed between the two groups in the mean duration and severity of pain before the intervention. After the intervention, a significant difference was observed between the groups in the severity of pain (P < 0.05), but no significant differences were observed in the duration of pain.DiscussionPeppermint capsules appear to be capable of reducing the severity of primary dysmenorrhea through certain analgesic mechanisms. Further studies are recommended to be conducted in order to confirm the use of peppermint in the relief of primary dysmenorrhea.