The FDA (Food and Drug Administration) has issued a warning about over-eating black licorice.
The FDA notes that licorice is high in a compound called glycyrrhizin, which is derived from the licorice plant root. When ingested, it can cause the potassium level in the body to fall. This can cause abnormal heart rhythms and even heart failure.
The FDA advises not to eat large amounts of black licorice at a time, especially if you are over 40.