Yes: real licorice raises blood pressure through glycyrrhizin, which makes kidneys retain sodium and dump potassium, a syndrome called pseudoaldosteronism. People with hypertension should avoid it.
The effect is dose- and duration-dependent: daily real-licorice candy, tea, or root supplements over weeks can push pressure up and potassium down far enough to cause weakness, palpitations, and dangerous rhythms, and the risk compounds with digoxin or potassium-wasting diuretics, which is why Merck Manual tells people with hypertension or heart disease to avoid licorice entirely. The good news is the fine print: most US licorice candy is anise-flavored and contains no glycyrrhizin, and DGL (deglycyrrhizinated) products strip the culprit compound; ingredient lists naming licorice extract or glycyrrhizin are the tell. If you have been consuming real licorice and your pressure crept up or you feel unusually weak, stopping it and telling your clinician is the fix; blood pressure and potassium typically recover within weeks. Licorice supplements sold for digestion or sore throat count too; check the label before assuming "herbal" means harmless.
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Common questions
Does licorice raise blood pressure?
Yes, genuine licorice is one of the few foods that reliably raises blood pressure, and the mechanism is well understood. The active compound, glycyrrhizin, blocks an enzyme that normally shields your body's mineralocorticoid receptors, so cortisol ends up acting like the hormone aldosterone: your kidneys retain sodium and water while excreting potassium. The result is a recognized syndrome called pseudoaldosteronism: rising blood pressure plus falling potassium, which can cause muscle weakness, dangerous heart rhythms, and in severe cases paralysis. Merck Manual's guidance is blunt: people with high blood pressure, heart disease, or those taking digoxin or potassium-wasting diuretics should avoid licorice. The doses that cause trouble are not exotic: daily consumption of real licorice candy, licorice tea, or licorice-root supplements over weeks is enough. Two important footnotes. Most American "licorice" candy is artificially flavored (anise) and contains no glycyrrhizin, so check ingredients for licorice extract or glycyrrhizin specifically; and DGL (deglycyrrhizinated licorice) products have the pressure-raising compound removed. If you have been eating real licorice regularly and feel weak, or your home readings have crept up, stop it and tell your clinician; potassium and pressure usually normalize within a few weeks of quitting.