Effect of fennel on primary dysmenorrhea: a systematic review and meta-analysis.

Background: One of the most common complaints for women is dysmenorrhea. Several studies investigated the treatment effects of medicinal plants on primary dysmenorrhea.

Objectives: This systematic review and meta-analysis investigates the effect of (Fennel) on pain in primary dysmenorrhea in comparison to non-steroidal anti-inflammatory drugs such as mefenamic acid.

Methods: PubMed, EMBASE, EBSCO Web of Science, Scopus, Cochrane library, Cochrane Central Register of Controlled Trials (CENTRAL), Science Direct, ProQuest, ISI Web of Science, Google Scholar, Magiran, SID, Iran Medex, and Irandoc were searched up to January 2019. Quality assessment of clinical trials was conducted using Jadad scoring system. Totally, 12 studies were entered in the meta-analysis. was calculated to determine heterogeneity. Fixed effects and/or random effects models were applied.

Results: Meta-analysis of these trials showed that intake decreased significantly the intensity of dysmenorrhea compared to the placebo (SMD -0.632; CI: -0.827 to -0.436; p<0.001; heterogeneity p=0.807; =0%; fixed effect model; seven articles). However, the effect of Mefenamic acid with was not different from each other (SMD=-0.214; CI: -0.446 to 0.017; p=0.07; heterogeneity p=0.58; =0%; fixed effect model; six trials).

Conclusion: The alleviates dysmenorrhea. Regarding the same effect of with NSAIDs, it is highly recommend to the women suffered from dysmenorrhea specifically the ones who have high tendency toward herbal medicine.