Licorice extract has always been recognized as a sweetener and a thirst quencher. Its nutritive value is overrated by many who consume significant amounts and are prone to complications. Glycyrrhetic acid, the active metabolite in licorice, inhibits the enzyme 11-ß-hydroxysteroid dehydrogenase enzyme type 2 with a resultant cortisol-induced mineralocorticoid effect and the tendency towards the elevation of sodium and reduction of potassium levels. This aldosterone-like action is the fundamental basis for understanding its health benefits and the wide spectrum of adverse effects. Herein, we present a comprehensive review of licorice along with the reported complications related to excess intake. Despite its apparent use in a few clinical scenarios, the daily consumption of licorice is never justified because its benefits are minor compared to the adverse outcomes of chronic consumption. The review highlights the importance of investigating the dietary habits and herbal remedies which are being used worldwide on cultural and habitual bases rather than reliable scientific evidence. Licorice is a US Food and Drug Administration (FDA) approved food supplement used in many products without precise regulations to prevent toxicity. Increased awareness among the public is required through TV commercials, newspapers, internet sites, magazines and product labels regarding the upper limit of ingestion and health hazards associated with excess intake. We hope that this review will serve as a warning message that should be transmitted from physicians to patients to avoid excessive licorice intake as well as a message to the FDA to start regulating the use of this substance.
Keywords: Licorice; glycyrrhizin; hyperaldosteronism; hypokalemic myopathy; pseudo-hyperaldosteronism.