* [[Colic]] in breast-fed infants. In a study, doctors treated 125 infants with colic, dividing them into one group that received a product containing fennel seed oil and one that received a placebo. The fennel seed product eliminated colic in 65 percent of the babies given it, compared with 24 percent of the placebo group.
*Stomach upset and indigestion.
* Breast Cancer : anethole, the organic substance known for its antimicrobial and antifungal properties. Now research proves just how powerful it is at fighting cancer. One study shows that anethole stops breast cancer cells from growing. Not only that. It also prevents these cells from surviving. In fact, the anethole can cause the breast cancer cells to kill themselves altogether in some cases. This means that at the very least it can slow the growth and spread of breast cancer
*Airway swelling.
*[[Bronchitis]].