Fennel seed is a spice that comes from the fennel plant, an herb that has been used for culinary and medicinal purposes for thousands of years. Fennel seed has a sweet, powerful, and licorice-like flavor that is common in Italian, Mediterranean, and Indian cuisine. Fennel seed may also have benefits for weight loss, cancer prevention, milk production, and digestion. Fennel seeds are rich in vitamin C, calcium, iron, magnesium, and potassium.