The Interaction Of Liquorice And Diuretics

One of the side effects of licorice is hypermineralocorticoidism, which can lead to hypertension. The reason for this is the glycyrrhizic acid content. Once ingested, glycyrrhizic acid is hydrolysed to form glycyrrhetinic acid. This compound selectively inhibits 1-b-hydroxysteroid dehydrogenase (also known as 11-beta-HSD2). [1-4]. 

With this enzyme blocked, cortisol doesn’t convert to the inactive cortisone and is allowed to build up in the body. This eventually leads to hypertension through binding of cortisol to the mineralocorticoid receptors in the kidneys, which increases water retention, and blood volume over time [5], mainly through renal sodium retention and loss of potassium [3]. 

The herb may act to reduce the effectiveness of diuretics through direct sodium retention activity. This action may reduce the effectiveness of diuretic medications like Thiazide-based diuretic medications used in the management of heart disease and hypertension [6].

These diuretic medications are well known for causing potassium depletion [7, 8], which is likely to develop into serious hypokalemia [9].

When using Glycyrrhiza, careful attention should be given on drug history taking of the patient. If they are currently taking diuretic medications to manage cardiovascular disease, or hypertension, it is recommended to avoid liquorice and substitute for another herb.



  1. Heilmann, P., Heide, J., Hundertmark, S., & Schöneshöfer, M. (1999). Administration of glycyrrhetinic acid: significant correlation between serum levels and the cortisol/cortisone-ratio in serum and urine. Experimental and clinical endocrinology & diabetes, 107(06), 370-378. 
  2. Krähenbühl, S., Hasler, F. E. L. I. X., Frey, B. M., Frey, F. J., Brenneisen, R. U. D. O. L. F., & Krapf, R. (1994). Kinetics and dynamics of orally administered 18 beta-glycyrrhetinic acid in humans. The Journal of Clinical Endocrinology & Metabolism, 78(3), 581-585.
  3. Serra, A, D.E. Uehlinger, P. Ferrari, B. Dick, B.M. Frey, F.J. Frey, & B. Vogt. (2002).  Glycyrrhetinic acid decreases plasma potassium concentrations in patients with anuria.  Journal of the American Society of Nephrologists 13 (1):191-196.
  4. Whorwood, C. B., Sheppard, M. C., & Stewart, P. M. (1993). Licorice inhibits 11 beta-hydroxysteroid dehydrogenase messenger ribonucleic acid levels and potentiates glucocorticoid hormone action. Endocrinology, 132(6), 2287-2292. Chicago.
  5. Guilliams, T. G., & Edwards, L. (2010). Chronic stress and the HPA axis. The standard, 9(2), 1-12.
  6. Musini, V. M., Rezapour, P., Wright, J. M., Bassett, K., & Jauca, C. D. (2012). Blood pressure lowering efficacy of loop diuretics for primary hypertension. The Cochrane Library.
  7. Fichman, M. P., Vorherr, H., Kleeman, C. R., & Telfer, N. A. N. C. Y. (1971). Diuretic-induced hyponatremia. Ann Intern Med, 75(6), 853-863.
  8. Spital, A. (1999). Diuretic-induced hyponatremia. American journal of nephrology, 19(4), 447-452.
  9. Strykers, P. H., Stern, R. S., & Morse, B. M. (1984). Hyponatremia induced by a combination of amiloride and hydrochlorothiazide. JAMA, 252(3), 389-389.