Licorice root does appear to have genuine effects on digestion, including promoting bowel movements, though the strongest evidence so far comes from animal studies rather than large human trials. In constipated mice, licorice water extract reduced the time to defecation, sped up intestinal motility, and increased the water content of stool. The mechanisms behind these effects involve changes in gut neurotransmitters, repair of the intestinal lining, and shifts in the gut microbiome. But before you reach for a bag of licorice candy or start brewing licorice tea to solve your constipation, the picture is more complicated than a simple yes.
What the Animal Research Actually Found
The most direct evidence linking licorice to bowel function comes from a study in which constipated mice were given a licorice water extract orally. The results were striking: the extract substantially reduced the time it took the animals to defecate, enhanced how quickly material moved through the intestines, and increased the water content of their feces. All three of those changes point toward a laxative-like effect.1Food Bioscience. Licorice water extract improves constipation by repairing the intestinal barrier and regulating the gut microbiota Wetter, softer stool that moves faster through the gut is essentially what any constipation remedy aims to achieve.
A separate study using a specific licorice extract (from Glycyrrhiza inflata, a related species) found that the extract improved gastric emptying in rats at a rate comparable to mosapride, a prescription drug used to treat sluggish stomach motility.2PubMed Central. Gastroprotective and gastric motility benefits of AD-lico/Healthy Gut™ Glycyrrhiza inflata extract Gastric emptying is an upper-GI process, not the same as having a bowel movement, but faster transit through the stomach can cascade into faster movement through the rest of the digestive tract.
The catch is that mouse and rat physiology, while informative, does not always translate directly to humans. No large, well-controlled human trial has tested whether licorice root extract reliably eases constipation in people. That does not mean the effect is imaginary; traditional medicine systems have used licorice for digestive complaints for centuries, and the animal data gives a plausible biological explanation. It does mean you should treat the finding as promising rather than proven.
How Licorice Appears to Work in the Gut
The mouse study went beyond just observing faster pooping and dug into why the extract worked. It found several overlapping mechanisms, which helps explain why licorice’s digestive effects can feel broad rather than narrowly targeted.
First, the extract raised levels of excitatory neurotransmitters in the gut, specifically serotonin (5-HT) and motilin, while lowering levels of inhibitory signals like vasoactive intestinal peptide and nitric oxide.1Food Bioscience. Licorice water extract improves constipation by repairing the intestinal barrier and regulating the gut microbiota Your gut has its own extensive nervous system, and the balance between signals that speed up contractions and signals that slow them down largely determines how quickly things move. By tipping that balance toward the excitatory side, licorice nudges the gut toward faster contractions.
Second, the extract repaired damage to the intestinal barrier. In the constipated mice, genes responsible for keeping the gut lining tight and intact (ZO-1, Occludin, and MUC2) were upregulated after licorice treatment, and populations of goblet cells, which produce protective mucus, were restored. A healthier intestinal lining makes it easier for the gut to manage water absorption properly, which in turn affects stool consistency.
Third, the extract increased a protein called aquaporin 3, a water channel in the colon. More of this protein means more water gets shuttled into the intestinal space, softening stool. At the same time, markers of low-grade intestinal inflammation went down.1Food Bioscience. Licorice water extract improves constipation by repairing the intestinal barrier and regulating the gut microbiota Chronic, low-level gut inflammation can slow motility and worsen constipation, so reducing it is another route to relief.
Finally, the study noted shifts in the gut microbiome after licorice treatment. The composition of bacteria in the colon changed in ways associated with healthier digestion. Research on gut bacteria and constipation is still evolving, but this finding lines up with a growing body of work suggesting that what you eat can reshape your microbiome in ways that affect how easily you go.
Licorice Root Versus Licorice Candy
This distinction matters enormously and trips up a lot of people. Most licorice candy sold in the United States and Europe contains little to no actual licorice root. The dominant flavor in many “licorice” products comes from anise oil, which tastes similar but is a completely different plant with different chemistry. Even products that do contain real licorice extract vary wildly in how much of the active compound, glycyrrhizin, they deliver.
The research on constipation used concentrated licorice water extract at a specific dose, not a handful of Twizzlers or licorice allsorts. If you are eating flavored candy and noticing a laxative effect, that is more likely coming from sugar alcohols like sorbitol (a common sweetener in sugar-free versions) or simply from the sugar load itself rather than from any licorice-specific compound. Conversely, if you are eating candy-aisle licorice and feeling nothing, that does not tell you much about what a real licorice root extract might do.
Traditional licorice preparations, whether teas, tinctures, or dried root slices, are a different category. These deliver meaningful amounts of glycyrrhizin and other bioactive compounds. If you want to test whether licorice genuinely helps your digestion, those are closer to what the research studied. But they also carry real risks, which brings us to the safety question.
Why Glycyrrhizin Can Be Dangerous
Glycyrrhizin is the compound most responsible for both licorice’s medicinal effects and its potential to cause harm. It inhibits an enzyme that normally inactivates cortisol in the kidneys, which leads to a cascade of effects mimicking a condition called apparent mineralocorticoid excess. In plain terms, too much glycyrrhizin makes your body hold onto sodium and dump potassium, pushing blood pressure up and potassium levels dangerously low.
Case reports describe patients developing severe hypokalemia (dangerously low potassium), high blood pressure, and metabolic alkalosis after consuming large quantities of licorice products over days to weeks.3PubMed Central. Trick or Treat? Licorice-Induced Hypokalemia: A Case Report Elderly patients appear particularly vulnerable to this triad of symptoms.4PubMed Central. Licorice Toxicity Presenting As Refractory Hypokalemia and Hypertension in an Elderly Patient The potassium depletion alone can cause muscle weakness, cramping, and in severe cases, heart arrhythmias.
A comprehensive safety assessment proposed an acceptable daily intake of glycyrrhizin ranging from about 0.015 to 0.229 mg per kilogram of body weight per day.5PubMed. Risk and safety assessment on the consumption of Licorice root (Glycyrrhiza sp.), its extract and powder as a food ingredient, with emphasis on the pharmacology and toxicology of glycyrrhizin For an average-sized adult, even the upper end of that range works out to a surprisingly small amount of licorice root. A single cup of strong licorice tea or a modest serving of real European-style licorice candy can exceed that upper limit depending on the product. The range is wide because individual sensitivity varies, and the authors were trying to capture both cautious and moderate thresholds.
The practical takeaway: occasional use is generally fine for most healthy adults. Daily, heavy, or prolonged use of real licorice products creates a genuine risk of the electrolyte disruptions described above. If you have high blood pressure, heart disease, or kidney problems, even occasional use deserves caution.
Drug Interactions Worth Knowing About
Licorice does not play well with several common medications. Because glycyrrhizin causes the body to lose potassium and retain sodium, it can amplify the effects of drugs that do similar things. Diuretics (water pills), which many people take for blood pressure, already deplete potassium. Combining them with regular licorice use can drive potassium levels even lower. Fludrocortisone, a corticosteroid that mimics the hormone aldosterone, shares enough of a mechanism with glycyrrhizin that taking both creates additive stress on your electrolyte balance.6Medsafe. Liquorice – All sorts of side effects and interactions
People on blood-thinning medications, certain heart drugs, or corticosteroids should talk to a pharmacist or doctor before using licorice products regularly. The interaction risk scales with the amount and frequency of licorice consumption. A single licorice tea once a month is unlikely to cause trouble; a daily licorice supplement on top of a diuretic prescription is a different story.
Pregnancy and Licorice
Pregnant people get a separate and stricter warning. A study following several hundred pregnancies in Finland found that heavy glycyrrhizin consumption during pregnancy was associated with more than double the risk of preterm delivery (before 37 weeks). When the researchers looked specifically at early preterm delivery (before 34 weeks), the risk was roughly three times higher among heavy consumers compared to those who consumed little or none.7PubMed. Preterm birth and licorice consumption during pregnancy
The exact mechanism is not fully pinned down, but it likely involves glycyrrhizin’s effects on cortisol metabolism. During pregnancy, the placenta normally keeps maternal cortisol from reaching the fetus in high concentrations. Glycyrrhizin interferes with the enzyme responsible for this protective barrier, potentially exposing the developing baby to higher cortisol levels than intended. Several Nordic countries now advise pregnant women to avoid or strictly limit licorice products, and this is one area where the precautionary approach seems well supported by data.
DGL: Licorice Without the Risky Part
The abbreviation DGL stands for deglycyrrhizinated licorice, which is licorice root that has had the glycyrrhizin removed. DGL was developed specifically to capture licorice’s digestive benefits while avoiding the blood pressure and potassium problems. It has been available as a supplement for decades, mainly marketed for upper-GI issues like heartburn, gastritis, and stomach ulcers rather than constipation specifically.
Recent pharmaceutical work has explored combining DGL with antacid compounds to create formulations that deliver both quick acid neutralization and slower mucosal protection. One study tested an effervescent granule pairing DGL with hydrotalcite (a mineral antacid) and found that the DGL component released over about an hour, suggesting it could offer sustained protective coverage for the stomach lining.8International Journal of Environmental Sciences. Design And Evaluation Of Gastroprotective Effervescent Granules Incorporating Hydrotalcite And Deglycyrrhizinated Licorice
Whether DGL helps with constipation specifically is less clear. The anti-constipation mechanisms identified in the mouse study involved the full licorice extract, not a glycyrrhizin-free version. Some of the gut-motility and neurotransmitter effects might still be present in DGL since licorice contains hundreds of bioactive compounds besides glycyrrhizin, but no study has directly tested DGL for constipation relief. If your primary goal is getting things moving and you want to avoid glycyrrhizin’s risks, DGL might offer partial benefit, but you would be operating on educated guesswork rather than solid data.
Traditional Medicine Got There First
Licorice root (Glycyrrhiza species) has been used medicinally for thousands of years across multiple cultures. In traditional Chinese medicine, it occupies a central role as a “harmonizing” herb, thought to strengthen the digestive system and moderate the effects of other herbs in a formula. The Pharmacopoeia of the People’s Republic of China lists licorice’s actions as supplementing spleen qi, clearing heat and toxicity, dispelling phlegm, and relaxing tension and pain, among others. It is indicated for conditions including deficiency of the spleen and stomach and fatigue.9Journal of Ethnopharmacology. Licorice: Resources, applications in ancient and modern times
In Ayurvedic and Greco-Arabic traditions, licorice root also shows up in digestive remedies. The overlap across unrelated medical traditions is interesting. These systems developed independently, yet each landed on licorice as something helpful for the gut. That does not constitute proof in a modern evidence-based sense, but it does suggest the plant has observable effects on digestion that people noticed long before anyone had a mouse model of constipation.
Modern research is essentially catching up to what traditional practitioners described, though with the advantage of being able to identify specific mechanisms. The neurotransmitter changes, intestinal barrier repair, and microbiome shifts documented in the mouse study offer a plausible biological explanation for what traditional medicine described in less precise terms.
Upper Versus Lower GI Effects
Most of the established research on licorice and digestion focuses on the stomach and upper digestive tract rather than the colon and bowel movements specifically. Licorice’s gastroprotective properties are well-documented: it can increase mucus production in the stomach lining, inhibit the growth of H. pylori (the bacterium behind many ulcers), and reduce acid-related damage. The rat study showing improved gastric emptying falls into this category, since gastric emptying reflects how quickly the stomach pushes food into the small intestine.2PubMed Central. Gastroprotective and gastric motility benefits of AD-lico/Healthy Gut™ Glycyrrhiza inflata extract
The constipation-specific research (the mouse study on licorice water extract) represents a newer line of inquiry that shifts attention downward, to the colon. The mechanisms it identified, particularly the changes in colonic water channels and the repair of goblet cells in the intestinal lining, are specifically lower-GI effects. This distinction matters because something that helps your stomach empty faster does not necessarily mean it will help you have a bowel movement. The mouse study suggests licorice does both, but through partly different pathways in different parts of the digestive system.
For someone dealing with constipation specifically, the lower-GI findings are the relevant ones. For someone with slow digestion, bloating, or a feeling of fullness after meals, the gastric emptying data might be more applicable. Licorice seems to touch multiple stages of digestion, which is unusual for a single-plant remedy and may explain its broad reputation in traditional medicine.
The Gut’s Sensory Wiring
One underappreciated dimension of how plant compounds affect digestion involves sensory receptors lining the gut. The digestive tract is full of receptor proteins called TRP channels that detect chemical signals, temperature changes, and mechanical stretch. These channels play roles in gut motility, pain signaling, and mucosal function throughout the entire alimentary canal.10PubMed Central. TRP channels in the digestive system Many plant-derived compounds interact with these channels, which is part of why spices, herbs, and other botanical substances can have such noticeable effects on your gut.
Licorice contains dozens of bioactive compounds beyond glycyrrhizin, including flavonoids, chalcones, and various phenolic acids. Some of these compounds are known to activate or modulate receptor systems in the gut, potentially contributing to the motility effects seen in the animal studies. This broad chemical complexity is one reason licorice’s digestive effects are hard to pin on a single molecule and why deglycyrrhizinated licorice might retain some activity even after the most famous compound has been stripped out. The gut’s sensory network is responsive to a wide palette of chemical signals, and licorice delivers quite a few of them simultaneously.
Researchers are still working out which specific licorice compounds activate which receptors and what the downstream effects are in humans. The animal data provides a reasonable starting framework, but the translation from mouse colon to human colon involves enough unknowns that anyone hoping for precise dosing guidance will be disappointed for now. What seems clear is that licorice root has real, measurable effects on gut function through multiple overlapping pathways, and the laxative effect reported anecdotally by many people who drink licorice tea has a biological basis that goes well beyond placebo.