What Conditions Does Licorice Cause? A Comprehensive Guide to Side Effects

November 30, 2025 •

3 min read

According to the FDA, consuming more than two ounces of black licorice daily for at least two weeks can cause an irregular heart rhythm, especially in individuals over 40. This key fact underscores the importance of understanding what conditions licorice cause and the critical role of moderation in its consumption.

Quick Summary

Excessive intake of licorice, particularly due to the compound glycyrrhizin, can lead to serious health issues such as dangerously high blood pressure, electrolyte imbalances like low potassium, and potentially life-threatening cardiac arrhythmias.

Key Points

Hypertension (High Blood Pressure): Excessive licorice intake causes sodium and water retention, which can significantly raise blood pressure, a serious risk for those with pre-existing hypertension.
Hypokalemia (Low Potassium): The glycyrrhizin in licorice causes the body to excrete potassium, leading to potentially dangerous electrolyte imbalances.
Cardiac Arrhythmias: The combination of high blood pressure and low potassium can trigger abnormal heart rhythms, including serious arrhythmias and, in extreme cases, cardiac arrest.
Fluid Retention (Edema): Sodium and water retention can cause swelling, particularly in the legs and ankles, and can exacerbate heart failure.
Pregnancy Complications: Licorice consumption is considered unsafe for pregnant women due to the risk of preterm delivery and potential adverse effects on fetal development.
Drug Interactions: Licorice can interfere with medications for heart failure, high blood pressure, and blood thinners like warfarin, neutralizing their effects or increasing toxicity.

The Core Mechanism: How Glycyrrhizin Affects the Body

Licorice's negative effects stem primarily from glycyrrhizin, a compound that provides sweetness but also mimics the hormone aldosterone. Glycyrrhizin inhibits an enzyme (11-ßHSD2) in the kidneys, preventing the breakdown of cortisol. This leads to excess cortisol activating mineralocorticoid receptors, creating 'pseudohyperaldosteronism'. Consequently, the body retains sodium and water while losing potassium, causing mineral imbalance and health problems.

Cardiovascular and Renal Complications

Excessive licorice stresses the cardiovascular and renal systems. Sodium and water retention increase blood volume and lead to high blood pressure, dangerous for those with pre-existing hypertension. Potassium loss (hypokalemia) is particularly concerning as it affects heart function. Low potassium can cause irregular heart rhythms (arrhythmias) that may lead to cardiac arrest in severe cases. Fluid retention also causes swelling (edema) in the limbs and can worsen congestive heart failure.

Neuromuscular and Other Systemic Effects

Electrolyte imbalances from licorice also impact the neuromuscular system. Significant hypokalemia can cause muscle weakness, lethargy, fatigue, cramping, and even flaccid paralysis (hypokalemic myopathy) in severe cases. Other symptoms include headaches, numbness, and tingling. Rarely, severe toxicity can cause rhabdomyolysis, potentially damaging the kidneys.

Drug and Supplement Interactions

Licorice can interact with medications and supplements. Its potassium-depleting effect is risky with diuretics like thiazides, leading to dangerously low potassium levels. For patients on digoxin for heart failure, low potassium increases toxicity and the risk of fatal arrhythmia. Licorice can also reduce the effectiveness of blood pressure medications and interfere with blood thinners like warfarin, potentially increasing clot risk. Corticosteroid effects can also be amplified.

Conditions to Avoid Licorice With

Certain individuals should avoid or limit licorice:

Pregnant and breastfeeding women: High intake during pregnancy is unsafe and linked to preterm delivery and potential developmental issues. Safety during breastfeeding is uncertain.
Individuals with heart or kidney conditions: Those with high blood pressure, heart failure, or kidney disease are sensitive to licorice's effects on fluid and potassium.
Those on specific medications: Avoid licorice if taking blood pressure medication, diuretics, warfarin, or digoxin due to dangerous interactions.

Licorice vs. Anise vs. DGL

The risks depend on glycyrrhizin content. True licorice contains it, while anise and deglycyrrhizinated licorice (DGL) do not.


Feature	True Licorice (Black)	Anise	DGL (Deglycyrrhizinated Licorice)
Source	Glycyrrhiza glabra root	Anise plant seed (unrelated)	Glycyrrhiza glabra root (processed)
Contains Glycyrrhizin?	Yes	No	No (removed during processing)
Effect on Blood Pressure	Can increase	No significant effect	No significant effect
Effect on Potassium	Can cause hypokalemia	No significant effect	No significant effect
Associated Side Effects	Hypertension, edema, cardiac arrhythmias	None related to glycyrrhizin	Possible mild skin irritation topically
Overall Safety	Use with caution, especially in large amounts	Generally considered safe	Possibly safe for short-term use

Conclusion

Excessive licorice consumption, particularly of products containing glycyrrhizin, carries significant health risks due to its ability to induce pseudoaldosteronism. This leads to high blood pressure, low potassium, fluid retention, and serious cardiac problems. Individuals with pre-existing conditions, those on certain medications, and pregnant women should be cautious or avoid licorice with glycyrrhizin. Risks are dose-dependent and increase with long-term use. Anise or DGL products are safer alternatives. Always consult a healthcare provider regarding dietary supplements.

For more information on the safety of herbal products, the National Center for Complementary and Integrative Health provides resources.

Frequently Asked Questions

The main substance is glycyrrhizin, a compound found in the licorice root (Glycyrrhiza glabra). In large quantities, it causes the body to retain sodium and water while losing potassium.

Both can cause issues, but the risk is directly related to the amount of glycyrrhizin. True licorice root and confections containing it are the culprits. Many candies in the U.S. use anise oil for flavor, which does not contain glycyrrhizin.

The FDA suggests that for people over 40, consuming more than two ounces (57 grams) of black licorice daily for at least two weeks may cause irregular heart rhythms. The specific risk depends on the product's glycyrrhizin concentration and individual health factors.

Early signs can include fatigue, muscle cramping or weakness, lethargy, headaches, and visible swelling (edema) in the limbs due to fluid retention.

No. DGL has the glycyrrhizin removed, eliminating the risk of raising blood pressure, lowering potassium, or causing the other side effects associated with standard licorice.

The first step is to immediately stop consuming all licorice-containing products. For serious symptoms like irregular heartbeats, severe muscle weakness, or extreme swelling, seek immediate medical attention.

Yes, many herbal teas contain licorice root extract with varying levels of glycyrrhizin. Regular consumption of these teas can pose the same risks as licorice candy.