Licorice has been used for centuries in traditional medicine across Europe and Asia.
The root of the licorice plant, a low-growing shrub mainly grown in Greece, Turkey, and parts of Asia, has long been used to help with health problems like heartburn, stomach ulcers, coughs, sore throats, and even viral infections like hepatitis.
Beyond its medical uses, licorice—especially black licorice—has become a popular sweet treat in many parts of the world.
But while black licorice may seem harmless, eating too much of it could actually be dangerous. A study by the U.S. Food and Drug Administration (FDA) found that people who eat two ounces of black licorice every day for at least two weeks could face serious heart problems, especially if they are over 40 years old.
The concern centers on a natural compound in licorice root called glycyrrhizin. This substance gives licorice its sweet taste, but it can also lower the amount of potassium in your body. Potassium is a vital mineral that helps the heart, muscles, and nerves work properly.
When potassium levels drop too low, it can lead to problems such as high blood pressure, tiredness, swelling, and even irregular heartbeats (called arrhythmias). In extreme cases, it may even lead to heart failure.
The FDA’s findings suggest that people over 40 or those with existing heart conditions are especially at risk. Even for healthy people, eating too much black licorice can cause trouble if consumed regularly over time. Earlier studies have also shown that black licorice can raise blood pressure, making it a concern for anyone trying to manage heart or kidney conditions.
The good news is that these effects are usually not permanent. If someone stops eating black licorice, their potassium levels usually go back to normal within a few days, and most symptoms fade away.
However, if someone feels unwell—such as having a racing or irregular heartbeat, muscle weakness, or unusual tiredness—they should stop eating black licorice immediately and see a doctor.
Another concern is how black licorice interacts with certain medications, herbs, and dietary supplements. Glycyrrhizin can affect how the body processes some drugs, which might make side effects worse or reduce how well the medicine works.
Because of these risks, the FDA recommends that people eat black licorice only in moderation. A small piece now and then is fine for most people, but regular or large amounts should be avoided—especially by older adults and those with heart issues.
This study is a good reminder that even natural products like licorice can have strong effects on the body. Just because something is plant-based or has been used for centuries doesn’t mean it’s always safe in large amounts.
So, while black licorice can still be enjoyed as a treat, it’s best to do so carefully. A little goes a long way—especially when it comes to protecting your heart.
If you care about blood pressure, please read studies about unhealthy habits that could increase high blood pressure risk, and people with severe high blood pressure should reduce coffee intake.
For more information about blood pressure, please see recent studies that early time-restricted eating could help improve blood pressure, and results showing plant-based foods could benefit people with high blood pressure.
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