Fennel (Foeniculum vulgare) has a long history of use in traditional medicine systems, particularly in the Mediterranean, Middle Eastern, and Indian cultures. It is commonly used for a variety of female reproductive concerns, including easing menstrual discomfort, supporting lactation, and alleviating symptoms of menopause. The seeds are often prepared as teas or decoctions for these purposes. This usage is rooted in the presence of phytoestrogens—plant compounds that can mimic estrogen in the body. In Ayurveda and traditional Persian medicine, fennel is recommended to regulate menstruation and promote fertility.

Scientific studies regarding fennel's effects on the reproductive system are limited and mostly preliminary. Some small clinical trials and animal studies suggest that fennel extracts may help reduce menstrual pain (dysmenorrhea) and improve some menopausal symptoms, likely due to its mild estrogenic activity. For example, a 2012 randomized clinical trial found that fennel was effective in reducing the intensity of primary dysmenorrhea compared to placebo. However, these studies often have small sample sizes and methodological limitations. There is also some research indicating fennel may increase milk secretion in breastfeeding women, although evidence is still inconclusive.

In summary, fennel's use for reproductive system support is primarily based on traditional use, with some emerging but not yet robust scientific support.