Background: Some clinical trials have revealed the effects of Matricaria chamomilla on premenstrual syndrome symptoms. This study was done to compare the effects of Matricaria chamomilla extract and mefenamic acid on the severity of premenstrual syndrome symptoms.

Materials and Methods: In a randomized double-blind clinical trial, 90 students completed daily rating form for the diagnosis of premenstrual syndrome symptoms and its severity for two consecutive cycles. After verification, they were randomly divided into two equal groups. The participants received one 100 mg capsule of Matricaria chamomillaor 250 mg mefenamic acid three times daily from day 21 of menstrual cycle till the beginning of the menstruation. They completed the daily symptom rating form at the same time.

Results: General severity reduction of symptoms was significantly greater among Matricaria chamomilla extract users (25±13.8 and 28±14.5%) than that among mefenamic acid users (14.8±18.5 and 16.2±18.2%) after the first and second cycles (p<0.05). Severity of emotional symptoms was significantly higher among Matricaria chamomilla extract users (30.1±26.6 and 33.4±25.3%) than that among mefenamic acid-users (11.6±25.7 and 10.7±26.8%) after two cycles intervention (p>0.05).Reduction of physical symptoms was not significantly different between the two groups (p>0.05).

Conclusion: Matricaria chamomilla reduces the severity of symptoms of premenstrual syndrome symptoms during treatment. Matricaria chamomilla effect on the severity of general and emotional symptoms of premenstrual syndrome symptoms is greater than that of mefenamic acid.