Who should not eat licorice? A guide to licorice safety

October 2, 2025 •

4 min read

According to the FDA, consuming just two ounces of black licorice daily for two weeks can cause serious health issues for those over 40. The root of this problem is a compound called glycyrrhizin, which is why there are specific groups of people who should not eat licorice.

Quick Summary

Certain individuals, including those with high blood pressure, heart or kidney disease, pregnant women, and people on specific medications, should steer clear of licorice due to its active compound, glycyrrhizin. This substance can dangerously raise blood pressure, alter potassium levels, and interact with crucial medicines.

Key Points

High Blood Pressure: Licorice can dangerously raise blood pressure by causing sodium and water retention, making it unsafe for those with hypertension.
Heart and Kidney Issues: Individuals with heart or kidney disease are at a heightened risk for complications due to licorice-induced electrolyte imbalances.
Pregnancy: Pregnant women should strictly avoid licorice, as excessive consumption is linked to a higher risk of preterm delivery.
Medication Interactions: Licorice can interfere with critical medications, including blood thinners (warfarin), diuretics, and heart drugs (digoxin).
Glycyrrhizin is the Culprit: The compound glycyrrhizin is the cause of these adverse effects, and licorice products with this compound removed (DGL) are safer alternatives.
Moderation is Key: Even for healthy individuals, large, consistent doses of licorice should be avoided to prevent dangerous side effects like hypokalemia.

The active compound: understanding glycyrrhizin

Licorice root contains glycyrrhizin, a natural sweetener that is much sweeter than sugar. This compound is responsible for licorice's distinct flavor but also for its adverse effects when consumed in large quantities. Glycyrrhizin acts by inhibiting an enzyme in the body, which can cause a cascade of health issues related to mineral and electrolyte balance, a condition known as pseudoaldosteronism. Understanding this mechanism is key to grasping why certain individuals must be cautious.

High blood pressure and heart disease patients

One of the most well-documented risks of licorice consumption is its effect on the cardiovascular system. Glycyrrhizin causes the body to retain sodium and water while excreting potassium. This can lead to a significant increase in blood pressure, making it particularly dangerous for those already managing hypertension. The resulting potassium deficiency, or hypokalemia, can trigger abnormal heart rhythms, known as arrhythmias, which are potentially life-threatening. Individuals with pre-existing heart failure or other heart conditions are especially vulnerable to these effects.

Individuals with kidney disease

The kidneys play a vital role in regulating the body's electrolyte balance. Since licorice disrupts this process by causing potassium loss and sodium retention, it can place a significant strain on the kidneys. For those with pre-existing kidney disease, this added pressure can worsen their condition and lead to severe complications. It is crucial for these patients to avoid licorice to protect their kidney function.

Pregnant and breastfeeding women

For expectant mothers, licorice consumption carries serious risks. Studies have linked excessive licorice intake during pregnancy to a higher risk of preterm delivery. While the exact mechanisms are still being studied, it is widely recommended that pregnant women avoid licorice root and products containing it. Since there is insufficient data on the safety of licorice during breastfeeding, mothers are advised to err on the side of caution and abstain from it during this period.

Those taking specific medications

Licorice can interact with several types of medication, reducing their effectiveness or increasing the risk of side effects. This is a critical consideration for anyone on a long-term medication regimen. Here are some of the most concerning interactions:

Digoxin: This medication treats heart failure and irregular heartbeats. The low potassium levels caused by licorice can increase the toxicity of digoxin, leading to dangerous heart problems.
Diuretics: Also known as 'water pills,' diuretics are used to treat high blood pressure and fluid retention. Licorice's effect on potassium can exacerbate the potassium-lowering effect of diuretics, leading to severe hypokalemia.
Warfarin: This blood thinner helps prevent blood clots. Licorice can interfere with its metabolism, potentially making it less effective and increasing the risk of clots.
Corticosteroids: Licorice can increase the effects and side effects of these anti-inflammatory drugs.

Choosing a safer alternative: DGL licorice

For those who enjoy the flavor or seek the digestive benefits of licorice but need to avoid glycyrrhizin, deglycyrrhizinated licorice (DGL) is an option. This form has had the glycyrrhizin removed, eliminating the risk of elevated blood pressure and potassium imbalances.


Feature	Standard Licorice	DGL Licorice
Glycyrrhizin Content	High	Trace or None
Effect on Blood Pressure	Can raise blood pressure significantly	No effect on blood pressure
Effect on Potassium Levels	Can cause dangerous hypokalemia	No significant effect on potassium
Safety for At-Risk Groups	Unsafe for individuals with hypertension, kidney/heart disease, or pregnant women	Generally considered safe for at-risk individuals, but always consult a doctor
Primary Use	Flavoring, herbal remedy (caution required)	Digestive health support

Recognizing the signs of licorice toxicity

If you have inadvertently consumed a large amount of licorice, be vigilant for these symptoms and contact a healthcare provider immediately if they occur:

Muscle Weakness: Due to low potassium, you may experience significant muscle weakness or paralysis.
Swelling: Sodium and water retention can cause edema, especially in the ankles and feet.
Irregular Heartbeat: Heart palpitations or a noticeably irregular rhythm can be a sign of hypokalemia.
Lethargy and Fatigue: Feeling unusually tired or lethargic is another symptom of electrolyte imbalance.
Headaches: High blood pressure can lead to headaches.

Conclusion: When in doubt, consult a professional

While licorice has been used for centuries, its potent active compounds mean it is not suitable for everyone. For those with high blood pressure, heart disease, kidney issues, or pregnancy, abstaining is the safest course of action. Always read product labels, as even licorice-flavored teas and candies can contain enough glycyrrhizin to be problematic. When in doubt, consult a healthcare provider, especially if you take medication or have an underlying health condition. For more details, refer to the guidance from the National Center for Complementary and Integrative Health.

Frequently Asked Questions

If you have high blood pressure, you should avoid eating black licorice that contains glycyrrhizin, as it can raise your blood pressure further and cause other health complications. Even small amounts can be risky, so it is best to consult your doctor.

No, licorice-flavored teas often contain glycyrrhizin and can pose a risk, particularly for those with hypertension or heart conditions. A 2015 case study highlighted a woman who developed hypertension from excessive licorice tea consumption. Always check the ingredients and consult a doctor if you have health concerns.

DGL stands for deglycyrrhizinated licorice, which is a form of licorice where the glycyrrhizin has been removed. It is generally considered safer and does not carry the same risks of affecting blood pressure or potassium levels. It's often used for digestive health.

Yes, licorice can interact with several medications, including digoxin, warfarin, diuretics, and corticosteroids. These interactions can decrease the effectiveness of your medication or cause harmful side effects. Always discuss licorice consumption with your doctor or pharmacist.

Initial signs can include fatigue, swelling (edema), headaches, and feeling lethargic. More severe signs include muscle weakness and an irregular heartbeat. If you experience these symptoms, especially if you have a pre-existing condition, seek medical attention.

Yes, large amounts of licorice extract consumed during pregnancy have been associated with an increased risk of preterm labor. Due to this risk, pregnant women are strongly advised to avoid licorice.

The FDA warns that consuming two ounces of black licorice daily for at least two weeks could cause issues for people over 40. However, susceptible individuals, like those with hypertension, can be affected by even smaller amounts. There is no universally safe amount, so caution is advised.