Licorice root has legitimate uses for digestive problems, sore throats, and inflammation, backed by a reasonable body of clinical evidence. It’s one of the most chemically complex medicinal plants known, with roughly 400 isolated compounds, including about 300 flavonoids. But it also carries real risks that many supplement labels gloss over, particularly for blood pressure. Here’s what the evidence actually supports.
Digestive Relief and Ulcer Healing
The strongest traditional use of licorice root, and the one with the most clinical backing, is for stomach and upper digestive problems. Licorice works on multiple fronts in the gut: it reduces stomach acid secretion, boosts the production of protective mucus, stabilizes the cells lining your stomach, and promotes the release of prostaglandins (compounds that help maintain the stomach’s inner barrier). This combination makes it genuinely useful for peptic ulcers and acid reflux symptoms.
For digestive use, the preferred form is deglycyrrhizinated licorice, commonly sold as DGL. This is licorice with its most problematic compound, glycyrrhizin, removed. DGL was actually shown to be more effective for healing ulcers than the glycyrrhizin-containing version, and it comes with almost none of the side effects. If you’re shopping for licorice to help with heartburn, bloating, or ulcer symptoms, DGL chewable tablets before meals are the standard approach. It’s also used for mouth ulcers (canker sores).
Sore Throat and Cough
Licorice root has been used for sore throats for centuries, and modern trials bear this out. In a randomized, double-blind study of 236 surgical patients (who tend to get severe sore throats from breathing tubes), gargling with a licorice solution before the procedure cut sore throat rates roughly in half compared to sugar water. At 90 minutes after the procedure, only 10% of the licorice group had a sore throat versus 35% in the control group. These effects held up at every time point measured.
For everyday use, licorice root tea or throat lozenges containing licorice extract can coat and soothe an irritated throat. The root acts as a demulcent, meaning it forms a protective film over inflamed tissue. It also has anti-inflammatory properties that go beyond simple coating. This is one of the safer short-term uses since gargling or sipping tea exposes you to relatively small amounts.
How Licorice Affects Cortisol
One of the more interesting things licorice does in your body is slow the breakdown of cortisol, your primary stress hormone. Glycyrrhizin blocks an enzyme in the kidneys that normally converts active cortisol into its inactive form, cortisone. In a study of healthy volunteers taking glycyrrhizin for seven days, cortisol levels in the kidneys rose measurably while cortisone dropped.
This is the basis for claims that licorice “supports adrenal health” or helps with fatigue. There’s a kernel of truth: if your cortisol is being cleared too quickly, licorice could theoretically help maintain levels. But this same mechanism is exactly what causes licorice’s side effects. More cortisol activity in the kidneys triggers the body to retain sodium, lose potassium, and raise blood pressure. The “adrenal support” effect and the blood pressure risk are two sides of the same coin.
Anti-Inflammatory and Immune Effects
Licorice root contains several flavonoid compounds with documented anti-inflammatory activity. These compounds reduce allergic responses and appear to protect liver cells from damage. The root’s broad anti-inflammatory profile is partly why it shows up in so many traditional medicine systems for such different conditions, from skin irritation to respiratory infections to joint pain.
Some of licorice’s flavonoids also show antimicrobial properties in lab studies, which may contribute to its effectiveness for throat infections and its historical use for respiratory illness. While these properties are real, most of the research is preclinical, meaning it’s been demonstrated in cells or animals rather than in large human trials.
Blood Pressure Risk Is Real
This is where licorice root demands respect. The World Health Organization previously suggested that 100 mg per day of glycyrrhizinic acid (the active form of glycyrrhizin) would be unlikely to cause problems. But a 2024 randomized crossover trial found that even this supposedly safe dose raised systolic blood pressure by an average of 3.1 mmHg, suppressed the hormone aldosterone by 45%, and suppressed renin by 30%. The researchers concluded that licorice may be “more potent than previously known” and that the safe intake limit may need to be lowered.
At higher doses, the risks are well established. Regular consumption of more than 3 grams of crude licorice root per day for longer than six weeks, or more than 100 mg of glycyrrhizin daily, can cause sodium and water retention, high blood pressure, and dangerously low potassium. In clinical literature, the amount of glycyrrhizin needed to produce these effects in otherwise healthy people ranges from 0.7 to 1.4 grams, which corresponds to roughly 10 to 14 grams of the raw root. But sensitive individuals can react to much less. As a general rule, licorice root containing glycyrrhizin should not be used continuously for longer than one month without monitoring.
Pregnancy Is a Clear Concern
Heavy licorice consumption during pregnancy has been linked to measurable effects on child development. Research following children of mothers who consumed large amounts of licorice found that their offspring scored roughly 7 points lower on verbal and performance IQ tests compared to children of low-consuming mothers. Girls born to heavy consumers showed earlier puberty, greater height, higher weight, and higher BMI. There was also an association with attention problems, though the study numbers were small.
The likely mechanism involves the same cortisol pathway described above. Glycyrrhizin disrupts an enzyme in the placenta that normally protects the fetus from the mother’s cortisol. When that barrier is weakened, the developing brain gets exposed to more stress hormone than it should. Given these findings, avoiding licorice root supplements and large amounts of real licorice candy during pregnancy is a straightforward precaution.
Drug Interactions to Know About
Licorice interacts meaningfully with several common medications. It can lower the blood levels of warfarin (a blood thinner), potentially making the drug less effective. It amplifies the effects of digoxin, a heart medication, which is dangerous because digoxin already has a narrow margin of safety. Because licorice promotes potassium loss, it can compound the effects of diuretics (water pills) that also deplete potassium, raising the risk of muscle weakness, cramping, or heart rhythm problems. If you take blood pressure medication of any kind, licorice root works directly against what your medication is trying to do.
DGL vs. Whole Licorice Root
The choice between these two forms comes down to what you’re using it for. DGL has the glycyrrhizin removed, which eliminates the blood pressure risk and makes it safe for longer-term digestive use. It’s the better option for acid reflux, stomach ulcers, and mouth sores. Clinical evidence shows it’s extremely low in toxicity and, for ulcer healing specifically, more effective than the whole extract.
Whole licorice root, whether as tea, powder, or standardized extract, retains the glycyrrhizin and all its benefits and risks. For short-term use like soothing a sore throat or a brief course for respiratory symptoms, whole licorice is fine for most healthy adults. But the key words are “short-term” and “healthy.” Anyone with high blood pressure, heart disease, kidney disease, or low potassium should stick with DGL or avoid licorice entirely. The same applies if you’re pregnant, taking diuretics, or on heart medications.
Licorice root tea typically contains less glycyrrhizin per serving than concentrated supplements or extracts, making it a lower-risk way to get the throat-soothing and mild digestive benefits. A cup or two of licorice tea on occasion is a very different proposition than taking standardized extract capsules daily for weeks.