Materials and Methods: This triple blind clinical trial was done in 2014 on 90 females visiting healthcare centers of Ardebil city, Iran. Women were complaining about excessive menstrual bleeding which occurred at least 3 months after placing IUDs. The first group received C. bursa-pastoris (700 mg) and the second group received mefenamic acid (500 mg) from first day of menstruation till bleeding completion, one every 8 hours. The questionnaire of sexual functioning was completed by the participants prior and 3 months after the treatment. The analysis of covariance (ANCOVA) test was used for comparing sexual functioning after the intervention among the studied groups with some adjustments on baseline scores.

Results: Mean (standard deviation) score of sexual functioning in mefenamic acid group was 23.39 (4.18) before the intervention which was increased to 24.24 ± 3.45 after applying intervention. In C. bursa-pastoris group, mean (standard deviation) score of sexual functioning was 21.40 (4.70) before the intervention which was increased to 24.85 ± 3.81 after applying intervention. According to the findings of study, mefenamic acid and C. bursa-pastoris were effective in improving the sexual functioning, but increase of sexual functioning score after the intervention was significant in the C. bursa-pastoris group (the justified mean difference: 0.60, 95% CI [-0.91?2.13], P = 0.01).

Conclusions: Capsella bursa-pastoris can be more effective compared to chemical drugs including mefenamic acid in increasing the sexual functioning of females with IUD.