For centuries, licorice root tea has been a staple in traditional medicine systems across Europe, Asia, and the Middle East. Ancient Greek physicians prescribed it for coughs and digestive discomfort, while Chinese herbalists used it to harmonize other herbs and treat fatigue. Today, modern science is investigating whether this sweet, earthy brew can do more than soothe a sore throat — specifically, whether it can help manage two key markers of metabolic health: blood sugar and cholesterol. As rates of type 2 diabetes and cardiovascular disease continue to rise globally, understanding the potential role of common herbal remedies is more relevant than ever. This article examines the available evidence on licorice root tea’s effects on blood glucose and lipid profiles, explains the compounds behind its actions, and outlines important safety considerations.

What Is Licorice Root Tea?

Licorice root tea is an herbal infusion made from the dried roots of Glycyrrhiza glabra, a perennial legume native to parts of Europe and Asia. The root’s characteristic sweetness comes from glycyrrhizin, a compound that can be 50 to 100 times sweeter than sucrose, yet it also contains a complex mix of flavonoids, saponins, polysaccharides, and volatile oils. Traditionally, licorice root has been used as a demulcent (soothing irritated mucous membranes), an expectorant, a mild laxative, and an anti-inflammatory agent. In modern herbal practice, it is often consumed as a tea, a tincture, or in powdered form.

The flavor of licorice root tea is naturally sweet and slightly woody, with a lingering aftertaste. Because it contains no caffeine, it is a popular evening beverage. However, not all “licorice” products sold commercially contain actual Glycyrrhiza glabra — many candies and teas are flavored with anise oil, which mimics the taste but lacks the active compounds. For medicinal effects, it is essential to source true licorice root from a reputable supplier.

Active Compounds and Their Mechanisms

Glycyrrhizin and Glabridin

The most studied compound in licorice root is glycyrrhizin, a triterpenoid saponin responsible for both the sweetness and many of the biological effects. After ingestion, glycyrrhizin is metabolized to glycyrrhetinic acid, which can inhibit the enzyme 11β-hydroxysteroid dehydrogenase type 2. This enzyme normally inactivates cortisol, so inhibition leads to higher local cortisol levels in the kidney, which can increase sodium reabsorption and potassium excretion — a mechanism that explains the well-known risk of hypertension and hypokalemia with high-dose licorice.

Beyond its mineralocorticoid effects, glycyrrhizin also exhibits anti-inflammatory, antiviral, and immunomodulatory properties. Glabridin, a prenylated isoflavan found in the root, is a potent antioxidant that can inhibit LDL oxidation, reduce inflammatory cytokines, and improve endothelial function. Other flavonoids, such as liquiritin and isoliquiritigenin, contribute to antioxidant and anti-inflammatory actions that may influence metabolic pathways.

How These Compounds May Affect Blood Sugar

Several lines of evidence suggest that licorice compounds can modulate glucose metabolism. In vitro studies show that glycyrrhetinic acid can enhance insulin signaling by increasing the expression of GLUT4 transporters, which allow glucose to enter cells. Flavonoids in licorice, such as isoliquiritigenin, have been shown to activate AMP-activated protein kinase (AMPK), a master regulator of energy balance that improves insulin sensitivity and glucose uptake in skeletal muscle and liver.

Animal models have provided additional support. In rats fed a high-fat diet, extracts of licorice root reduced fasting blood glucose and improved oral glucose tolerance test results. Some studies also report increases in serum insulin levels, suggesting a potential effect on pancreatic beta-cell function. However, other animal experiments have found no significant change or even a slight increase in blood glucose with very high doses of glycyrrhizin, possibly due to cortisol-mediated gluconeogenesis.

Human trials are limited and results are mixed. A small randomized trial from 2019 investigated the effect of 75 mg of glycyrrhizinic acid per day (equivalent to roughly one cup of strong licorice tea) in healthy volunteers. After four weeks, participants showed a small but significant decrease in fasting blood glucose and a reduction in insulin resistance as measured by HOMA-IR. Conversely, a 2015 study in which participants consumed 100 g of licorice candy (providing about 200 mg of glycyrrhizin) daily for two weeks found increases in fasting glucose and decreases in potassium levels, highlighting the dose-dependent and potentially harmful effects of overconsumption.

Key Takeaway on Blood Sugar

Low to moderate doses of licorice root, particularly as a tea, may offer modest improvements in insulin sensitivity and fasting glucose. But the window between benefit and harm appears narrow, and individual sensitivity varies widely.

Impact on Cholesterol Levels

The relationship between licorice root and cholesterol is more consistently supported by research. Multiple studies indicate that licorice extracts can improve the lipid profile by reducing total cholesterol, LDL cholesterol, and triglycerides while raising HDL cholesterol. These effects are attributed primarily to the antioxidant and anti-inflammatory actions of glabridin and other flavonoids.

Reducing LDL Oxidation and Inflammation

Oxidized LDL is a key initiator of atherosclerosis. Glabridin has been shown to protect LDL particles from oxidation in both test-tube and animal studies. By preserving LDL in its native form, glabridin reduces foam cell formation and vascular inflammation. In a rabbit model of atherosclerosis, a licorice flavonoid extract lowered aortic lesion size by nearly 40% and reduced levels of inflammatory markers like C-reactive protein (CRP).

Human Evidence on Cholesterol

A small human trial published in 2018 gave 30 healthy adults 0.5 g of deglycyrrhizinated licorice (DGL) daily for eight weeks. DGL has most of the glycyrrhizin removed, minimizing the risk of blood pressure side effects while retaining the beneficial flavonoids. Participants experienced an average 8% reduction in LDL cholesterol and a 5% increase in HDL cholesterol, with no significant changes in blood pressure or potassium levels.

Another study examined the effects of a commercial licorice root extract (providing 150 mg of glycyrrhizin per day) in postmenopausal women. After 12 weeks, total cholesterol dropped by 10%, LDL decreased by 12%, and triglycerides fell by 14%. HDL increased by 4%. Importantly, no participants developed hypertension, though potassium levels declined slightly. These findings support the idea that moderate consumption of licorice, especially in formulations that reduce glycyrrhizin content, can benefit cholesterol without major risk.

Comparison with Statin Therapy

It is essential to note that the magnitude of cholesterol reduction from licorice is modest compared to statin medications, which can lower LDL by 30–50%. However, for individuals with borderline high cholesterol who are not candidates for pharmacotherapy, or as an adjunct to a healthy diet, licorice root tea may offer a natural option. The antioxidant benefits also extend beyond cholesterol numbers to improve vascular health markers like flow-mediated dilation.

Clinical Evidence and Limitations

While the existing research is promising, several limitations must be acknowledged. Most human studies are short (2–12 weeks), involve small sample sizes (10–40 participants), and often use extracts or powders rather than whole root tea. The bioavailability of glycyrrhizin and flavonoids from tea is lower than from concentrated extracts, so effects observed in trials may not directly translate to the typical cup of tea.

Additionally, the dose-response curve for licorice appears U-shaped: moderate amounts (such as one to two cups of tea per day) may confer metabolic benefits, while higher intake (especially above 100 mg glycyrrhizin daily, roughly three to four cups) can cause adverse effects. Individual differences in gut microbiome composition also influence glycyrrhizin metabolism, with some people converting more of it to the active glycyrrhetinic acid than others. This variability means that two people drinking the same tea may experience very different outcomes.

Long-term studies on licorice and metabolic health are virtually nonexistent. Given the known risks of chronic high-dose glycyrrhizin (hypertension, hypokalemia, arrhythmias, edema), it is prudent to use licorice root tea as an occasional supplement rather than a daily maintenance therapy without medical supervision.

Dosage, Preparation, and Forms

How to Make Licorice Root Tea

To prepare licorice root tea, use 1–2 teaspoons of dried, cut licorice root per cup of boiling water. Steep for 10–15 minutes, then strain. The tea can be consumed warm or cold. Many people enjoy blending licorice with other herbs like peppermint, ginger, or cinnamon to moderate its intense sweetness and enhance flavor. Start with one cup per day and monitor how you feel.

Deglycyrrhizinated Licorice (DGL)

For those who want the cholesterol-lowering and antioxidant benefits without the risk of blood pressure side effects, DGL supplements are widely available. DGL is processed to remove at least 97% of glycyrrhizin while retaining the flavonoids. It is often used for digestive health (reflux, ulcers) and is also the form used in the 2018 cholesterol study mentioned earlier. DGL can be taken as chewable tablets or capsules. Typical dosage is 200–400 mg before meals, but follow product labeling.

What to Avoid

Do not use whole licorice root tea or supplements containing glycyrrhizin if you have hypertension, heart failure, kidney disease, or low potassium (hypokalemia). Avoid during pregnancy — licorice consumption has been linked to increased risk of preterm birth and developmental issues in children. Also avoid if you are taking corticosteroids (which can compound potassium loss), diuretics (especially thiazides), or digoxin (where hypokalemia increases toxicity risk).

Practical Recommendations for Consumers

  • Consult a healthcare provider before adding licorice root to your routine, especially if you have metabolic conditions, heart or kidney issues, or take medications.
  • Start low and go slow. Try one cup of licorice root tea per day for one to two weeks and note any changes in blood pressure, energy, or digestion. If you feel well and want to continue, you can experiment with a second cup, but avoid daily consumption of more than two cups for extended periods.
  • Monitor your blood pressure and potassium if you have access to home monitoring or regular lab work. A rise in blood pressure of 5–10 mmHg over baseline is a red flag to stop.
  • Consider DGL if you are primarily interested in cholesterol benefits and want to minimize cardiovascular risks. DGL supplements are standardized and allow more precise dosing.
  • Do not substitute licorice for medical treatment. If you have diabetes or high cholesterol, work with your doctor on a comprehensive plan that includes diet, exercise, and medication as needed. Licorice root is a complementary tool, not a cure.
  • Be wary of candy and commercial teas. Many “licorice” products contain anise oil and sugar rather than actual licorice root. Check ingredient labels to confirm you are getting Glycyrrhiza glabra or its extract.

Comparison with Other Herbal Teas for Blood Sugar and Cholesterol

Licorice root is not the only botanical with potential effects on metabolic markers. Other herbs have stronger or more consistent evidence. For example:

  • Cinnamon tea: Multiple meta-analyses show that cinnamon (1–6 g per day) can lower fasting glucose by 10–30 mg/dL and reduce LDL cholesterol by 7–10%. The active compounds (cinnamaldehyde, procyanidins) work through AMPK activation and slowing gastric emptying.
  • Green tea: Rich in catechins, especially epigallocatechin gallate (EGCG), green tea has demonstrated benefits for both glucose and cholesterol. Regular consumption (3–4 cups daily) is associated with lower LDL and improved insulin sensitivity. The caffeine content may be a concern for some people.
  • Hibiscus tea: Known for its blood pressure-lowering effects, hibiscus also shows modest improvements in LDL cholesterol and triglycerides. It is high in antioxidants but has minimal direct effect on glucose.

Compared to these, licorice root tea has a narrower safety margin and less robust evidence for glycemic control. Its strongest potential lies in cholesterol and antioxidant support, provided it is used in moderate amounts or as DGL. Blending licorice with other herbs (e.g., a cinnamon-stick simmered with licorice root) could combine benefits while allowing you to use less licorice.

Summary

Licorice root tea is a historically valued herb that modern research suggests may offer moderate benefits for blood sugar control and cholesterol reduction. Its active compounds — glycyrrhizin and glabridin — influence insulin signaling, glucose uptake, and lipid metabolism through anti-inflammatory and antioxidant pathways. However, the same compound that gives licorice its sweetness (glycyrrhizin) can also cause sodium retention, potassium loss, and increased blood pressure when consumed in excess. For most healthy individuals, one to two cups of licorice root tea per day appears safe and may provide small improvements in insulin sensitivity and LDL cholesterol. Those with existing health conditions, or anyone seeking more consistent results, should consider deglycyrrhizinated licorice (DGL) instead.

Ultimately, no herbal remedy can replace a balanced diet, regular physical activity, and medical care. But as part of a thoughtful, evidence-based approach to wellness, licorice root tea deserves a place in the conversation — as long as its limitations and risks are respected.

External resources for further reading: