Licorice is LIKELY SAFE for most people when taken by mouth in amounts found in foods. Licorice is POSSIBLY SAFE when taken by mouth in larger amounts for medicinal purposes and when applied to the skin for a short amount of time. However, it is
POSSIBLY UNSAFE when taken by mouth in large amounts for more than 4 weeks or in smaller amounts long-term. Consuming licorice daily for several weeks or longer can cause severe side effects including high blood pressure, low potassium levels, weakness, paralysis, and occasionally brain damage in otherwise healthy people. In people who eat a lot of salt or have heart disease, kidney disease, or high blood pressure, as little as 5 grams per day can cause these problems.
Other side effects of licorice use include tiredness, absence of a menstrual period in women, headache, water and sodium retention, and decreased sexual interest and function in men.
People who chew tobacco flavored with licorice might develop high blood pressure and other serious side effects.
Special Precautions & Warnings:
Heart disease: Licorice can cause the body to store water, and this can make congestive heart failure worse. Licorice can also increase the risk of irregular heartbeat. Don't consume licorice if you have heart disease.
High blood pressure: Licorice can raise blood pressure. Don't consume large amounts of it if you have high blood pressure.
Low potassium levels in the blood (hypokalemia): Licorice can lower potassium in the blood. If your potassium is already low, licorice might make it too low. Don't use licorice if you have this condition.
Kidney disease: Overuse of licorice could make kidney disease worse. Don't use it.
Sexual problems in men: Licorice can lower a man's interest in sex and also worsen erectile dysfunction (ED) by lowering levels of a hormone called testosterone.
http://www.webmd.com/vitamins-supplements/ingredientmono-881-licorice.aspx?activeingredientid=881