How licorice changes the kidneys’ signals
The risk comes from glycyrrhizin, a natural substance in licorice root. After the body processes it, the resulting compounds can interfere with an enzyme in the kidneys that normally limits the effect of cortisol, a hormone circulating in the blood. When that safeguard is weakened, cortisol can act more like aldosterone, a hormone that tells the kidneys to hold on to sodium and water and send more potassium into the urine.
That shift can lower potassium in the blood. It may also raise blood pressure and cause fluid retention. The effect is not an allergy or an immediate poison-like reaction: it develops as the body’s handling of salt and potassium changes.
Why the amount and duration matter
A small taste is not the same as repeatedly eating substantial amounts. Risk depends on how much licorice-derived glycyrrhizin a person consumes and for how long; products vary in their ingredients, and “black licorice” can also be flavored with anise rather than licorice root. The label’s ingredients can help distinguish them.
Low potassium can cause muscle weakness, cramps, or unusual tiredness. If it becomes severe, it can interfere with the heart’s electrical coordination and trigger an abnormal rhythm. People with heart or kidney problems, or those taking medicines that affect potassium or blood pressure, may have less room for the body to absorb this added strain.
The practical lesson is to treat real-licorice candy as more than a flavor when it is eaten regularly or in large quantities: a habit that seems harmless can gradually alter the kidney’s balance of potassium and salt.
