HIGH BLOOD PRESSURE
Carbenoxolone, a compound derived from licorice root, has been used to help healing of peptic ulcers. The disadvantage of this compound is that in 1/3 of patients it raises blood pressure, increases fluid retention and promotes potassium loss.
This is a problem only with licorice, and not with other plants with similar flavors such as anise and fennel.
Licorice, anise and fennel share one common flavor component, anethole. This is NOT what causes problems with high blood pressure.
Licorice root contains several other compounds not found in anise and fennel. One of these is glycyrrhizin which is 50 times sweeter than sugar.