Hate to spoil the post-Halloween candy binge, but the Food and Drug Administration has a spooky warning for adults: Don't overindulge in black licorice, especially if you're 40 or older.

A compound in licorice root can affect your heart rhythm. Older adults who eat 2 ounces of black licorice a day for at least two weeks risk landing in the hospital with an irregular heart rhythm, or arrhythmia, according to the FDA.

FDA experts say the culprit in black licorice is glycyrrhizin, the natural sweetening compound in licorice root. (The warning doesn't apply to red licorice, which only looks like licorice, but contains little or no licorice root.)

Glycyrrhizin can cause potassium levels in the body to fall, causing some people to experience an abnormal heartbeat, as well as high blood pressure, swelling from fluid retention, muscle weakness and congestive heart failure.

You might want to check the ingredient label. Many licorice-flavored products made in the U.S. do not actually contain any real licorice. Instead, they use anise oil, which has a similar smell and taste.

The FDA also says black licorice can interact with some medications, herbs and dietary supplements. Consult your doctor if you have questions.