Licorice is an herb that is also known by the scientific name, Glycyrrhiza glabra. According to the University of Maryland Medical Center (UMMC), it has been used for centuries in both Eastern and Western medical practices to treat numerous ailments, from respiratory problems to stomach problems. Licorice extract is a concentrated product of the licorice plant, available in liquid or powdered root form. While licorice can have medicinal benefits, it can also produce negative side effects that you, as a potential licorice extract user, should be aware of.
High Blood Pressure
One of the effects of licorice extract can be high blood pressure. A study published in the March–April 2000 edition of the "American Journal of Nephrology" reports that licorice, even in small doses, can cause hypertensive encephalopathy, which is high blood pressure accompanied by nausea, vomiting, dizziness, visual problems and headache.
The National Institutes of Health report that licorice has an effect on the levels of hormones in the body. Hormones that are out of balance can cause serious side effects. One of these negative effects is an electrolyte imbalance, which can affect the body's level of sodium and potassium, causing swelling and fluid retention, and can contribute to high blood pressure.
An electrolyte imbalance can also cause arrhythmias, or irregular heartbeats, heart failure, kidney damage and muscle weakness. Licorice extract can also affect a woman's levels of estrogen, which can cause a change in the menstrual cycle.
Interaction With Medications
As a potent herb, licorice can have an adverse affect on different medications. The UMMC lists some of these medications as blood pressure medicines, such as ace-inhibitors or diuretics; digoxin, which is used to treat congestive heart failure; laxatives, as licorice can increase a potassium loss with laxative use; insulin, as licorice can intensify the negative side effects of insulin, such as excessively low blood sugar; and oral birth control, as licorice is reported to cause high blood pressure and potassium loss when taken while using oral contraceptives.