Licorice root contains compounds that affect digestion, inflammation, and hormone balance, but most human evidence comes from short studies or traditional use rather than large clinical trials

Licorice root has been used in traditional medicine for thousands of years, particularly in Chinese and Ayurvedic practice, to soothe the digestive tract and reduce inflammation. The plant contains glycyrrhizin, a compound roughly 50 times sweeter than sugar, along with flavonoids and other molecules that appear to interact with your gut lining and immune response. What makes licorice different from many herbal remedies is that some of its effects have been measured in human studies—but the evidence is often limited to small groups, short timeframes, or specific populations like people with ulcers or acid reflux.

The gap between traditional reputation and modern evidence matters because licorice is not inert. Regular consumption can raise blood pressure and lower potassium in some people, effects that show up more clearly in research than the benefits do. Understanding what licorice actually does—and what remains unclear—helps you decide whether it fits your situation.

Key Takeaways

  • Licorice root may reduce stomach acid and protect the stomach lining, based on small human studies and animal research, but evidence is strongest when combined with other compounds rather than used alone.
  • The compound glycyrrhizin can raise blood pressure and lower potassium levels with regular use, a risk that increases at doses above 100 mg per day and in people with existing hypertension or kidney issues.
  • Licorice appears to have anti-inflammatory effects in the mouth and throat, supported by studies in people with mouth ulcers and sore throats, though the effect size is modest.
  • Most human studies on licorice last weeks to a few months, so long-term safety and effectiveness remain unclear.

How licorice affects stomach acid and the digestive tract

Licorice root does not directly neutralize stomach acid the way an antacid does. Instead, research suggests it works by thickening the mucus layer that protects your stomach lining and possibly by increasing the production of protective compounds called prostaglandins. A 2009 review in the Journal of Medicinal Food found that licorice reduced ulcer formation in animal models and showed modest benefit in small human studies of people with peptic ulcers, particularly when combined with standard ulcer medications.

The catch is that most human evidence comes from studies using deglycyrrhizinated licorice (DGL)—a processed form with most of the glycyrrhizin removed—rather than whole licorice root. DGL appears safer for regular use because it avoids the blood pressure and potassium effects, but it is also less studied. A 2015 systematic review found that DGL showed promise for mouth ulcers and sore throat, but the number of high-quality human trials was small, and effect sizes were modest compared to standard treatments.

Blood pressure and potassium: the side effect that matters most

Glycyrrhizin, licorice's main active compound, can cause your body to retain sodium and lose potassium by mimicking the hormone aldosterone. This effect is dose-dependent: occasional use of licorice tea or candy is unlikely to cause problems, but regular consumption of whole licorice root—especially above 100 mg of glycyrrhizin per day—can raise blood pressure and lower serum potassium within weeks. People with existing hypertension, heart disease, or kidney problems face higher risk.

A 2017 review in Phytotherapy Research documented cases of hypokalemia (low potassium) and hypertension in people consuming licorice regularly, with symptoms ranging from muscle weakness to irregular heartbeat. The risk is real enough that many medical organizations recommend avoiding whole licorice root if you take blood pressure medications or have a history of high blood pressure. DGL avoids this problem because the glycyrrhizin has been removed, which is one reason it is often recommended over whole root for long-term use.

Anti-inflammatory effects in the mouth and throat

Licorice has been shown to reduce inflammation and pain in the mouth and throat in several small human studies. A 2015 trial published in Phytotherapy Research found that a licorice mouthwash reduced the severity and duration of aphthous ulcers (canker sores) compared to placebo, with participants reporting pain relief within a few days. Another study found that licorice lozenges reduced sore throat pain and swelling in people with pharyngitis, though the effect was modest and comparable to standard throat lozenges.

The mechanism appears to involve both the anti-inflammatory properties of licorice's flavonoids and glycyrrhizin's ability to increase local mucus production. However, these studies were small (typically 30 to 60 participants) and short (one to two weeks), so the effect size in real-world use may vary. Licorice is not a replacement for antibiotics if you have a bacterial infection, but it may provide symptom relief alongside standard treatment.

Immune function and respiratory health: emerging but limited evidence

Animal studies and test-tube research suggest that licorice compounds may enhance certain immune responses and reduce viral replication, but human evidence is sparse. A small 2011 study found that licorice extract reduced the duration and severity of cough in people with upper respiratory infections, but the study was not placebo-controlled and involved only 30 participants. More recent research has looked at licorice's potential role in respiratory infections, but most work remains in animal models or cell cultures.

Claims that licorice boosts immunity or prevents viral infection are not yet supported by large human trials. The traditional use of licorice in respiratory formulas may reflect its ability to soothe inflamed throat tissue and increase mucus production rather than a direct antiviral effect. If you are considering licorice for a respiratory condition, it should complement—not replace—medical treatment.

Hormone effects and interactions with medications

Glycyrrhizin can affect hormone metabolism, particularly by increasing cortisol levels and interfering with the enzyme that breaks down cortisol in your kidneys. This can lead to a condition called pseudoaldosteronism, where your body retains sodium and loses potassium even though your aldosterone levels are normal. People taking corticosteroids (like prednisone) face increased risk of side effects when combining them with licorice.

Licorice also interacts with several medication classes: it may reduce the effectiveness of blood pressure medications, increase the risk of low potassium when combined with diuretics, and interfere with the metabolism of certain anticoagulants and immunosuppressants. If you take any regular medications, particularly for blood pressure, heart rhythm, or hormone-related conditions, check with your doctor or pharmacist before using licorice root. DGL is safer in this regard because it lacks glycyrrhizin, but you should still disclose it.

Dosage, forms, and what the research actually measured

Licorice is sold as dried root, tea, extract, powder, and lozenges, with glycyrrhizin content varying widely. Most studies that showed benefit used doses of 1 to 2 grams of dried root per day or 75 to 200 mg of glycyrrhizin, typically for 2 to 12 weeks. DGL products usually contain 380 to 760 mg per dose, taken two to three times daily before meals.

The problem is that commercial products are not standardized: a licorice tea bag may contain far less active compound than a concentrated extract, and labeling often does not specify glycyrrhizin content. If you want to use licorice for a specific purpose—such as mouth ulcers or digestive comfort—look for products that list glycyrrhizin percentage or choose DGL if you plan to use it regularly. Keep in mind that most human studies lasted weeks to a few months, so safety and effectiveness beyond that timeframe are not well established.

Frequently Asked Questions

Is licorice root safe to use every day?

Whole licorice root is not recommended for daily long-term use because glycyrrhizin can accumulate and raise blood pressure or lower potassium over time. DGL (deglycyrrhizinated licorice) is safer for regular use because the glycyrrhizin has been removed, but you should still check with your doctor if you have hypertension, heart disease, or take medications. Occasional use—a cup of licorice tea a few times a week—is generally considered safe for most people.

Can licorice help with acid reflux?

Licorice may reduce stomach acid symptoms by protecting the stomach lining and increasing mucus production, but most evidence comes from small studies or from DGL combined with other compounds. It is not a replacement for proton pump inhibitors or other acid-reducing medications. If you have chronic acid reflux, talk to your doctor before adding licorice; it may help alongside standard treatment but should not replace it.

What is the difference between licorice root and DGL?

DGL is licorice root with most of the glycyrrhizin removed through processing. Whole licorice root contains glycyrrhizin, which can raise blood pressure and lower potassium with regular use. DGL avoids these side effects, making it safer for long-term use, but it is also less studied and may be less potent for some effects. If you plan to use licorice regularly, DGL is the safer choice.

Does licorice interact with blood pressure medications?

Yes. Glycyrrhizin can raise blood pressure and may reduce the effectiveness of blood pressure-lowering drugs. It also increases potassium loss, which is risky if you take diuretics. If you take any blood pressure or heart medications, do not use whole licorice root without checking with your doctor or pharmacist first. DGL is a safer alternative if you want to use licorice.

How long does it take to feel the effects of licorice?

For digestive symptoms like mouth ulcers or sore throat, studies show effects within a few days to a week. For other uses, the timeframe is less clear because most human studies lasted only weeks to a few months. If you do not notice improvement within two weeks of regular use, licorice may not be effective for your situation, and you should explore other options.