Fennel tea may aid healthy digestion, and treat bloating, gas, or cramps, and may also act as a diuretic. According to herbalists, fennel seed is an effective aid to digestion. It can help the smooth muscles of the gastrointestinal system relax and reduce gas, bloating, and stomach cramps.
 
Fennel seeds may not only add depth and flavor to your recipes but also help curb appetite.
 
Eating fennel and its seeds may benefit heart health in a number of ways, as they’re packed with fiber — a nutrient shown to reduce certain heart disease risk factors like high cholesterol.
Fennel and its seeds also contain nutrients like magnesium, potassium, and calcium, which play important roles in keeping your heart healthy
 
The wide array of powerful plant compounds in fennel may help protect against chronic diseases, including certain cancers.
For example, anethole — one of the main active compounds in fennel seeds — has been found to exhibit cancer-fighting properties.
 
Fennel has been shown to have galactogenic properties, meaning it helps increase milk secretion. Research suggests that specific substances found in anethole, such as dianethole and photoanethole, are responsible for the galactogenic effects of the plant. Fennel may increase milk secretion and blood levels of prolactin — a hormone that signals the body to produce breast milk. This is very beneficial for breast feeding women that struggle to produce enough milk for their baby. 
 
May have antibacterial properties. Studies show that fennel extract inhibits the growth of potentially harmful bacteria and yeasts, such as Escherichia coli, Staphylococcus aureus, and Candida albicans.
May reduce inflammation. The powerful antioxidants in fennel, such as vitamin C and quercetin, can help reduce inflammation and levels of inflammatory markers.
May benefit mental health. Animal studies have found that fennel extract may reduce aging-related memory deficits.
May relieve menopausal symptoms. A review of 10 studies noted that fennel may improve sexual function and satisfaction in menopausal women, as well as relieve hot flashes, vaginal itching, dryness, pain during sex, and sleep disturbances.