Theoretically! »adults over 40 who eat more than two ounces of black licorice a day for two weeks could suffer heart problems like arrhythmia«You know its possible to poison yourself with black.licorice.
I definitely eat more than two ounces (57 grams) per day, its more like ½ pound per day, but i do that only a few times a year (birthday and Christmas) until my supply runs out. Back in Germany i was eating Black Licorice literally daily and my body should have gotten used to it to a point where it generates craving feelings…
More dangerous than glycyrrhizin is the Ammonium-Chloride salt that is added to "salty" black licorice (DZ=doubel zalt) may cause more damage.