Licorice (Yashtimadhu): The Sweet Root for Throat and Stomach

Licorice (Glycyrrhiza glabra, yashtimadhu in Sanskrit) is Ayurveda's great soothing root: its best-established benefits concern an irritated throat, dry cough and acid stomach discomfort. Its naturally sweet flavor — glycyrrhizin is far sweeter than sugar — coats and soothes mucous membranes, which explains its presence in countless throat lozenges and teas.

But licorice is also a herb whose limits you need to know: taken in excess or long-term, glycyrrhizin can raise blood pressure and lower potassium levels. Used well — short courses, modest doses — it genuinely helps. Used carelessly, it's a real problem.

What are the benefits of licorice?

• Throat and voice: its most consensus use. As tea, decoction or a stick to chew, licorice soothes an irritated throat, dry cough and hoarseness. Tradition calls it the herb of singers and speakers.
• Stomach and acidity: Ayurvedic tradition uses it against heartburn and acid discomfort (amlapitta); preliminary data support a protective effect on the stomach lining. The DGL (deglycyrrhizinated) form is often preferred for long-term use here.
• Respiratory tract: a gentle traditional expectorant, it appears in winter blends for congestion.
• Skin: used externally, licorice extracts help soothe redness and even out skin tone — a common cosmetic use, with modest data.

In the Ayurvedic framework, licorice soothes Vata and Pitta: sweet, cooling and unctuous, it's a typically anti-Pitta herb. Kapha, already soft and moist, should use it in moderation. It's also classed a rasayana for the voice and tissues.

How to take licorice: tea, powder or DGL?

For guidance only — practices as commonly seen, as a short course:

Form	Typical dose	For what
Tea / root decoction	1 to 2 g of root per cup, 1 to 2 cups a day	Throat, dry cough, digestive comfort
Powder	1 to 3 g per day, in warm water or milk	Traditional Ayurvedic use
DGL extract (glycyrrhizin-free)	Per product, before meals	Sensitive stomach, longer-term use
Root stick to chew	Occasional	Throat, sweet cravings, breath

For tea, prefer a proper short decoction over a simple infusion: put the cut root in cold water, bring to a bare simmer for 5 minutes, then let it sit covered for 10 minutes. The hard, fibrous root doesn't release its compounds well from water simply poured over it. In India, yashtimadhu is also taken as a powder with unheated honey for the throat, or with ghee for the stomach — Ayurveda chooses the carrier (anupana) based on the desired effect.

The golden rule: no more than 4 to 6 weeks in a row for glycyrrhizin-containing forms, and stick to modest doses. European health authorities recommend limiting daily glycyrrhizin intake; in practice, an occasional cup poses no problem for a healthy person, but generous, prolonged daily use does.

Does licorice work for heartburn?

This is one of its strong suits. Ayurveda sees heartburn as excess Pitta fire; licorice, sweet and cooling, is one of its classic correctives, often paired with the cooling diet described in our article on acidity and heartburn. For regular use, the DGL form has the advantage of sidestepping the blood-pressure issue. Two honest limits: clinical data remain preliminary, and frequent heartburn (several times a week, for weeks) suggests reflux that deserves a doctor, not prolonged self-treatment.

Licorice and blood pressure: the real contraindication

This is THE safety point to remember. Glycyrrhizin disrupts the kidneys' regulation of potassium and sodium: in excess, it causes high blood pressure, low potassium, water retention, and in severe cases, heart rhythm disturbances. This isn't theoretical: cases are regularly reported in heavy licorice consumers (candy included).

• High blood pressure: avoid. If your blood pressure is elevated or treated, avoid non-deglycyrrhizinated licorice, even as regular tea.
• Pregnancy: no. Regular licorice consumption is discouraged during pregnancy. Breastfeeding: medical advice.
• Interactions: diuretics, corticosteroids, digoxin, blood-pressure medication — talk to your doctor or pharmacist.
• Kidney or heart disease: medical advice is essential before any use.
• Everyone: short courses, modest doses, and watch for hidden sources (candy, non-alcoholic anise drinks, blended teas).

General precaution rules (quality, at-risk groups) are detailed in our safety and precautions guide.

Licorice dangers: doses, durations and what the studies measured

Glycyrrhizin blocks a kidney enzyme that normally keeps cortisol away from the aldosterone receptor. The body then retains sodium and water and loses potassium, a picture known as pseudo-hyperaldosteronism: higher blood pressure, swelling, muscle weakness and, in marked cases, heart rhythm disturbances. It is generally reversible on stopping, but can take several weeks to resolve. The risk grows with dose, duration and individual sensitivity, and it concerns the whole root, not the DGL form: a product not labeled "DGL" should be assumed to contain glycyrrhizin.

Situation	Prudent guideline	Note
Occasional consumption	A few days, moderate dose	Low risk in a healthy person
Prolonged regular consumption	Beyond 4 to 6 weeks continuously	Blood-pressure monitoring advised; better to take a break
High daily dose	Large amounts of root or concentrated extract, every day	Significant risk even over a few weeks
Adding up multiple sources	Real black licorice candy, some anise-flavored drinks, herbal teas	The intakes add up, often without the person realizing it

Even a modest dose has a measurable effect. In a randomized crossover trial by af Geijerstam and colleagues, published in 2024 in the American Journal of Clinical Nutrition, 28 healthy young volunteers took licorice providing 100 mg of glycyrrhizic acid a day for two weeks, or a control product: home systolic blood pressure rose by 3.1 mmHg on average, while renin fell by about 30% and aldosterone by about 45% (see the study). The authors conclude that licorice is more potent than previously thought.

Pregnancy is the other documented signal. In a Finnish case-control study by Strandberg and colleagues, published in 2002 in the American Journal of Epidemiology, 95 women who gave birth preterm were compared with 107 who delivered at term: heavy glycyrrhizin intake (500 mg a week or more) was associated with a more than twofold risk of preterm delivery (see the study). This is an observational association, but together with a plausible mechanism it is why regular consumption of real licorice is best avoided during pregnancy; an occasional candy or cup is not the exposure studied. Artificially flavored "licorice" candy generally contains no glycyrrhizin.

How to use it safely day to day

Three simple, reasonable uses: an occasional throat tea in winter (licorice, ginger and a slice of lemon, on the model of our ginger-lemon-honey tea); a gentle decoction for a few days when your voice is tired; and the DGL form before meals for a sensitive stomach, over a few weeks. In winter, it pairs well with the anti-cold kit alongside tulsi and ginger. Buy an organic root, cut or powdered, from a trustworthy brand: licorice is a root, so it's sensitive to soil quality. On price, cut organic root is generally inexpensive from an herbalist or health-food store — enough for several short courses.

How long it takes and how long to use it

For a sore throat, licorice (yashtimadhu) acts quickly: a tea or decoction brings relief within a few minutes thanks to its soothing effect on the mucous membranes. For digestive comfort and heartburn, the effect needs more consistency: allow 1 to 2 weeks of daily intake for a clear change, especially with the DGL (deglycyrrhizinated) form taken before meals.

One critical point shapes both timelines: licorice containing glycyrrhizin is never taken as an extended course, whatever effect you are after — a safety principle that outweighs the simple question of timing.

What timeline by form and use?

Use	First signs	Recommended maximum course
Tea for a sore throat, dry cough	A few minutes to a few hours	Occasional, a few days per episode
Digestive comfort, heartburn (DGL)	A few days to 1 week	Several weeks, DGL better suited to longer use
Whole root with glycyrrhizin, regular use	1 to 2 weeks	4 to 6 weeks maximum, then a break

This is why the DGL form, stripped of glycyrrhizin, is preferred for extended digestive use: it lets you judge an effect over several weeks without the blood-pressure risk tied to the whole root.

What are the first signs licorice is working?

• Throat and voice: an almost immediate soothing, often from the very first tea;
• Dry cough: reduced irritation within a few hours to a few days of repeated use;
• Heartburn: digestive comfort that generally sets in after a few days to a week of regular intake before meals.

Why never extend a licorice course beyond a few weeks?

Glycyrrhizin, present in the whole root, disrupts the kidneys' regulation of potassium and sodium as it accumulates: it is an effect that depends on cumulative duration of use, not just the one-off dose. That is why the rule of 4 to 6 weeks maximum, followed by a break, outweighs any "longer for a better effect" logic — on the contrary, extending a course raises the risk without demonstrated extra benefit.

When should you conclude licorice is not working for you?

If a sore throat does not improve after a few days of repeated teas, or if heartburn persists after one to two weeks of DGL taken before meals at a proper dose (see our article licorice, benefits and precautions), it is reasonable to see a doctor rather than extend use. A cough lasting more than two to three weeks or frequent heartburn despite adjustments call for medical advice, as detailed in our article acid reflux and heartburn.

How to give it the best chance of working within these timelines

• Prefer a real decoction to a simple infusion for the cut root, which otherwise releases its compounds poorly;
• Take DGL before meals rather than after, for the best effect on the stomach lining;
• Respect the course length rather than extending use hoping for a stronger effect;
• Avoid hidden sources of glycyrrhizin (candy, anise-flavored drinks) during the course, which skew your assessment of the real dose.

Precautions to know during the trial period

Non-deglycyrrhizinated licorice is firmly discouraged with high blood pressure, cardiac treatment, pregnancy or kidney disease, whatever the intended duration. The DGL form removes most of this risk and is better suited to extended digestive use. The full picture of precautions is in our safety guide.