What are the side effects of licorice root?

When used in large amounts for medicinal purposes, licorice root may raise blood pressure and make congestive heart failure worse, according to WebMD. Conditions that are sensitive to hormones, such as breast cancer and ovarian cancer, may also be worsened. Licorice can decrease testosterone levels in men.

People with potassium deficiencies shouldn't use licorice root, as it decreases potassium levels, according to WebMD. Pregnant women who consume 250 grams or more of licorice while pregnant are at risk for early delivery or miscarriage. People with hypertonia and kidney problems should also avoid licorice, as it can make these conditions worse.