Who Should Not Eat Black Licorice?

December 3, 2025 •

3 min read

According to the U.S. Food and Drug Administration (FDA), a person aged 40 or older who eats more than 2 ounces of black licorice daily for at least two weeks could be hospitalized with an irregular heart rhythm. This stark warning underscores a crucial question: who should not eat black licorice, and what makes it potentially dangerous for certain individuals?

Quick Summary

Certain individuals with pre-existing conditions like high blood pressure, heart disease, and kidney issues should avoid black licorice. The root contains glycyrrhizin, which can cause potassium levels to fall, leading to serious health problems. It can also interfere with various medications.

Key Points

Heart and Blood Pressure Issues: People with high blood pressure, heart disease, or irregular heart rhythms should avoid black licorice due to its effect on blood pressure and potassium levels.
Kidney Concerns: Individuals with kidney disease are at higher risk because licorice can strain compromised kidney function and cause serious electrolyte imbalances.
Medication Interactions: Black licorice can interfere with medications for heart failure (e.g., digoxin), high blood pressure, and blood thinners (e.g., warfarin).
Pregnancy and Breastfeeding: Pregnant women should avoid black licorice as it has been linked to preterm delivery and potential developmental issues in some studies.
Older Adults: The FDA warns that those over 40 are at increased risk of irregular heart rhythms from excessive black licorice consumption.
Glycyrrhizin is the Culprit: The dangerous effects are caused by the compound glycyrrhizin, which can lower potassium levels and increase blood pressure.
Moderation is Key for Low-Risk Individuals: For healthy individuals, small amounts of black licorice are generally considered safe, but excessive consumption should always be avoided.

The Hidden Dangers of Black Licorice

For many, black licorice is an innocuous treat. However, the extract used for its flavor contains glycyrrhizin. In excessive amounts, glycyrrhizin can cause serious health issues, including increased blood pressure, low potassium levels, arrhythmias, and swelling. Therefore, certain people should completely avoid black licorice.

Who Needs to Be Especially Cautious?

The primary concerns with black licorice are its effects on blood pressure and potassium. Individuals with certain pre-existing conditions are at higher risk.

Individuals with high blood pressure (hypertension): Glycyrrhizin can increase blood pressure by causing the body to retain sodium and lose potassium. This can be particularly risky for those already managing hypertension.
Those with heart conditions: Low potassium levels (hypokalemia) can lead to irregular heart rhythms (arrhythmias). This is very serious for people with heart disease and can even cause cardiac arrest in severe cases.
People with kidney disease: Licorice's impact on sodium and potassium can stress already compromised kidneys. The effects of glycyrrhizin can also build up, further impacting kidney function.
Pregnant or breastfeeding women: Glycyrrhizin has been linked to a higher risk of preterm delivery and potential effects on a child's development. Health authorities in Finland advise pregnant women to avoid it, and avoidance is recommended during breastfeeding due to a lack of data.
Anyone over the age of 40: The FDA notes that individuals over 40 are more susceptible to the adverse effects of excessive black licorice, likely due to a higher prevalence of blood pressure and heart issues in this age group.

Medications That Interact with Black Licorice

Black licorice can interfere with several medications.

Diuretics: Combining licorice with diuretics can lead to dangerously low potassium levels.
Blood pressure medications: Licorice can raise blood pressure, making these medications less effective.
Digoxin: Low potassium from licorice can increase the toxicity of this heart medication.
Blood thinners (warfarin): Licorice may interfere with warfarin, potentially increasing clot risk.
Corticosteroids: Licorice can enhance the effects and side effects of corticosteroids.

Black Licorice vs. Other Candies: A Comparison

Many licorice-flavored candies, like red licorice, are made with anise oil and do not contain glycyrrhizin.


Feature	Real Black Licorice (with Glycyrrhizin)	Imitation Licorice (e.g., Red Licorice)
Active Compound	Contains glycyrrhizin	Contains anise oil or artificial flavors
Effect on Blood Pressure	Can raise blood pressure due to sodium retention and potassium loss	No effect on blood pressure
Potassium Levels	Can cause hypokalemia (low potassium)	No effect on potassium levels
Cardiac Risks	Poses a risk of irregular heart rhythms and heart failure in large amounts	No known cardiac risk from flavor compound
Pregnancy Risks	Advised against for pregnant women	Generally considered safe (but still high in sugar)
Risk of Medication Interaction	High, especially with cardiac, blood pressure, and diuretic drugs	Low
Root Source	Made from the Glycyrrhiza glabra plant root	Flavored artificially, sometimes with anise

Is There a Safe Amount?

The amount of glycyrrhizin varies, making a universal safe limit difficult. The FDA's guideline of avoiding more than two ounces daily for two weeks for those over 40 is helpful, but even smaller amounts can be risky depending on health status and medications. Moderation is advised for everyone, and avoidance for at-risk groups.

Conclusion

Black licorice poses health risks for certain groups due to glycyrrhizin. Those with heart, kidney, or blood pressure issues, as well as pregnant women and older adults, should be cautious. Distinguishing between real licorice and anise-flavored candies is also important. If you are in an at-risk group or have concerns about medication interactions, consult a healthcare provider before eating black licorice. The risks of this candy can be significant.

Disclaimer

The information provided is for educational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare provider before making any changes to your diet, especially if you have pre-existing health conditions or are taking medication.

Frequently Asked Questions

The compound responsible for the health risks associated with black licorice is glycyrrhizin. It can cause potassium levels to fall and blood pressure to rise, particularly with excessive consumption.

Yes, excessive consumption of black licorice can cause a drop in potassium levels, which in turn can lead to irregular heart rhythms or arrhythmia, and in rare, severe cases, heart attack or cardiac arrest.

Individuals with high blood pressure, heart disease, or kidney problems are at the highest risk. People over 40 and pregnant women should also be especially cautious.

The FDA warns that eating more than two ounces of black licorice per day for at least two weeks could be problematic for those aged 40 and older. However, a safe amount varies greatly, so moderation is always advised.

No, most red licorice products do not contain the glycyrrhizin compound found in black licorice. They are typically flavored with anise oil or artificial ingredients, so they do not carry the same health risks related to blood pressure and potassium levels.

Yes, black licorice can interact with medications for blood pressure, diuretics (water pills), and heart failure medication like digoxin. It can also interfere with blood thinners and corticosteroids.

DGL is a form of licorice with the glycyrrhizin removed. Without this compound, DGL does not carry the same risks related to blood pressure and potassium levels. However, it is primarily used as a supplement, and it's best to consult a doctor before use.