Fennel (Foeniculum vulgare) is an herb with yellow flowers. The dried seeds are used in food. The dried seeds and oil are also used as a supplement.

Fennel is native to the Mediterranean, but is now found throughout the world. As a supplement, it might relax the colon, and also appears to contain an ingredient that may act like estrogen in the body. As a spice, fennel has an anise-like taste.

People use fennel for menstrual cramps. It is also used for excessive crying in infants (colic), indigestion, and symptoms of menopause.