What happens when you take furosemide with licorice?
Furosemide (Lasix) is a loop diuretic, and licorice root (Glycyrrhiza glabra or Glycyrrhiza uralensis) contains glycyrrhizin. Each lowers potassium through a different pathway, so stacking them can push potassium too low.
- Furosemide blocks sodium reabsorption in the loop of Henle, so the kidneys excrete sodium, water, and potassium together. Potassium loss is built into how the drug works.
- Glycyrrhizin from licorice is converted in the body to glycyrrhetinic acid, which inhibits the kidney enzyme 11-beta-hydroxysteroid dehydrogenase type 2 (11-beta-HSD2).
- Normally that enzyme converts cortisol into inactive cortisone so it cannot stimulate the mineralocorticoid (aldosterone) receptor. With the enzyme blocked, cortisol accumulates and acts like aldosterone.
- The body then retains sodium and water, blood pressure can rise, and extra potassium is excreted into the urine. This is called apparent mineralocorticoid excess or pseudoaldosteronism.
- On top of furosemide's own potassium wasting, the two mechanisms combine and raise the risk of clinically significant hypokalemia, sometimes with muscle weakness, cramps, or arrhythmia.
Why is this important?
This is a well-documented combination. Human case reports describe hypokalemia, muscle weakness, and in severe cases paralysis, rhabdomyolysis, and dangerous cardiac arrhythmias in people who combined licorice with a diuretic or consumed a lot of licorice on their own. The published cases that became severe typically involved diuretic co-use, which describes many furosemide users.
Licorice exposure is easy to miss. People take licorice root extract for digestive complaints, sore throat, or "adrenal support" without thinking of it as a medicine. Glycyrrhizin is also used as a sweetener and flavoring in some teas, candies, herbal cough syrups, throat lozenges, and chewing tobacco. Even modest daily amounts of real licorice, taken regularly, have produced pseudoaldosteronism in otherwise healthy adults.
Recovery is the rule once licorice is stopped, but it can be slow: glycyrrhetinic acid clears from the body slowly, so blood pressure and potassium may take many weeks to months to fully normalize. That makes avoiding the problem more practical than treating it.
What should you do?
The simplest rule is to avoid glycyrrhizin-containing licorice while you take furosemide, and to keep your care team informed.
Before starting or changing furosemide
- Tell your prescriber and pharmacist about any licorice products you use, including herbal teas, lozenges, cough syrups, and adrenal or digestive blends.
- The same warning applies to thiazide diuretics, corticosteroids, and digoxin, so mention those too.
Every day on furosemide
- Skip licorice root tea, tincture, tablets, and adrenal-support blends containing Glycyrrhiza glabra or G. uralensis.
- Read candy and product labels before buying. Twizzlers and most U.S. "licorice" candy are flavored with anise oil and contain no glycyrrhizin; authentic European licorice, Dutch drop, and salted licorice usually contain real glycyrrhizin.
- Check herbal cough syrups, throat sprays, and lozenges, since many use licorice extract as a demulcent.
- If you need licorice for digestive use, choose deglycyrrhizinated licorice (DGL), which has the glycyrrhizin removed and does not cause pseudoaldosteronism.
After any change, watch for warning signs
- Increasing leg swelling despite the same furosemide dose, rising blood pressure, muscle weakness or cramps, unusual fatigue, or palpitations can signal low potassium or fluid retention.
- Seek medical care promptly if these appear, and review them with your doctor or pharmacist before assuming a brief licorice exposure was harmless.
Which specific products are affected?
The interaction applies to any licorice product containing glycyrrhizin: licorice root teas (for example Yogi Egyptian Licorice or Traditional Medicinals Organic Licorice Root), bulk licorice root, licorice tinctures and tablets, adrenal-support blends, Chinese herbal formulas containing gan cao, traditional Japanese kampo formulas, and throat-coat blends with licorice. Hidden sources include authentic European licorice candy, Dutch drop, salted licorice, herbal cough syrups, throat sprays and lozenges, and certain chewing tobaccos.
Deglycyrrhizinated licorice (DGL) chewables and capsules are not affected, because the glycyrrhizin has been removed. Twizzlers and most U.S. licorice candy are also fine, since they use anise oil rather than real licorice.
On the medication side, the same caution extends to other loop diuretics (torsemide, bumetanide) and to thiazides (hydrochlorothiazide, chlorthalidone). Potassium-sparing diuretics such as spironolactone, eplerenone, amiloride, and triamterene partially blunt the effect by acting at the mineralocorticoid receptor or distal tubule, but they do not make licorice clearly safe.
The science behind it
The mechanism and the clinical risk are supported by human reports. A 2024 case series in the International Journal of Molecular Sciences describes pseudohyperaldosteronism due to licorice and reviews how glycyrrhetinic acid inhibits 11-beta-HSD2 to produce apparent mineralocorticoid excess (Int J Mol Sci. 2024;25(13):7454). A 2025 case report of licorice-induced pseudohyperaldosteronism documents the same syndrome in an individual patient (Clin Case Rep, PMC11725489). A separate report describes a hypertensive crisis with target-organ injury triggered by glycyrrhizin (Medicine (Baltimore), PMC5882392), illustrating how severe the mineralocorticoid effect can become. Across these reports, the cases that progressed to severe hypokalemia, arrhythmia, or rhabdomyolysis generally involved concurrent diuretic use, which is the heart of this interaction.
Frequently Asked Questions
Is Twizzlers licorice a problem with furosemide?
No. Twizzlers and most U.S. "licorice" candy are flavored with anise oil and contain no glycyrrhizin, so they do not drive this interaction. Authentic European licorice, Dutch drop, and salted licorice do contain glycyrrhizin and should be avoided.
Is DGL licorice safe to take with furosemide?
DGL (deglycyrrhizinated licorice) has the glycyrrhizin removed, so it does not cause pseudoaldosteronism and is the safer choice for digestive use. If a product does not clearly say "deglycyrrhizinated" or "DGL," assume it contains glycyrrhizin.
How would I know if my potassium is getting too low?
Warning signs include muscle weakness or cramps, unusual fatigue, palpitations, increasing leg swelling despite the same furosemide dose, and rising blood pressure. These warrant prompt medical attention; potassium is checked with a simple blood test.
How long does the effect last after I stop licorice?
Glycyrrhetinic acid clears slowly, so blood pressure and potassium can take many weeks to months to fully normalize after stopping. Don't assume a brief exposure has worn off quickly.
Do other licorice-flavored or herbal products count?
They can. Herbal cough syrups, throat sprays and lozenges, Chinese formulas with gan cao, Japanese kampo formulas, and some chewing tobaccos may contain glycyrrhizin. Check labels and ask your pharmacist if you are unsure.
Should I stop my furosemide instead?
No. Furosemide is usually prescribed for an important reason. The right move is to stop the glycyrrhizin-containing licorice and tell your doctor or pharmacist, not to change your prescribed diuretic on your own.
Key takeaways
- Furosemide and glycyrrhizin from licorice each lower potassium by different mechanisms; combined, they can cause significant hypokalemia.
- Avoid glycyrrhizin-containing licorice (root teas, tinctures, tablets, real licorice candy, adrenal blends, gan cao formulas) while on furosemide.
- DGL is glycyrrhizin-free and a safer option for digestive use; Twizzlers and most U.S. licorice candy contain no real licorice.
- Watch for muscle weakness, cramps, fatigue, palpitations, swelling, or rising blood pressure, and seek care if they appear.
- Disclose all licorice use to your doctor and pharmacist, and review any concerns with them rather than adjusting furosemide yourself.