Licorice, specifically the “real” kind containing a compound called glycyrrhizin, interacts with a surprisingly long list of medications. The core problem is that glycyrrhizin causes your body to retain sodium and lose potassium, which raises blood pressure and disrupts electrolyte balance. These effects can amplify or interfere with dozens of common drugs, sometimes dangerously.
This applies to real licorice root found in teas, supplements, chewing tobacco, and some imported candies. Most American-made licorice candy is flavored with anise oil and doesn’t contain glycyrrhizin. If a product lists “licorice root” or “licorice extract” as an ingredient, it likely contains the active compound.
Blood Pressure and Heart Medications
Because licorice raises blood pressure on its own, it directly works against the medications designed to lower it. ACE inhibitors, beta-blockers, calcium channel blockers, and other blood pressure drugs can all become less effective when you’re consuming licorice regularly. The result is blood pressure that stays elevated despite medication, which your doctor may misinterpret as needing a higher dose.
The interaction with heart rhythm medications is potentially more serious. Licorice depletes potassium, and low potassium levels make the heart more vulnerable to irregular rhythms. If you’re taking digoxin for heart failure or an abnormal heartbeat, low potassium dramatically increases the risk of toxicity, which can cause dangerous rhythm disturbances. The same potassium-lowering effect makes licorice risky alongside antiarrhythmic drugs that depend on stable electrolyte levels to work safely.
Diuretics (Water Pills)
This is one of the most concerning combinations. Many diuretics already cause potassium loss as a side effect. Adding licorice on top creates a compounding effect where potassium drops faster and further than either would cause alone. Severely low potassium can lead to muscle weakness, cramping, fatigue, and in extreme cases, cardiac arrest.
Thiazide diuretics and loop diuretics are the main concern here. If you take a potassium-sparing diuretic, licorice may counteract its potassium-preserving benefit, undermining the whole reason it was prescribed.
Blood Thinners and Antiplatelet Drugs
Licorice can interfere with warfarin by affecting how your body processes the drug. Compounds in licorice influence liver enzymes responsible for metabolizing warfarin, potentially increasing or decreasing the drug’s blood-thinning effect. Either direction is problematic: too much thinning raises bleeding risk, and too little allows dangerous clots. If you’re on warfarin, even moderate licorice consumption can make your levels unpredictable.
Corticosteroids
Glycyrrhizin slows the breakdown of cortisol in your body, effectively amplifying the effects of corticosteroid medications like prednisone and hydrocortisone. This means you could experience stronger side effects than expected, including more fluid retention, higher blood pressure, greater blood sugar spikes, and more significant immune suppression. The interaction essentially makes your prescribed dose behave like a higher one.
Hormone-Related Medications
Licorice has mild estrogen-like activity, which means it can interfere with hormone therapies. If you’re taking birth control pills or hormone replacement therapy, licorice may increase the risk of side effects associated with higher estrogen levels, including headaches, fluid retention, and elevated blood pressure. For the same reason, it can potentially reduce the effectiveness of medications used to treat estrogen-sensitive conditions.
The hormonal effects also extend to testosterone. Licorice has been shown to reduce testosterone levels in some studies, which could interfere with testosterone replacement therapy or affect conditions where hormonal balance matters.
MAO Inhibitors and Other Antidepressants
Licorice contains compounds that may have mild MAO-inhibiting properties of their own. Combining it with MAO inhibitor antidepressants could theoretically intensify side effects. The blood pressure elevation from licorice is also a concern with MAO inhibitors, which already carry a risk of hypertensive crisis when combined with certain foods and substances.
SSRIs and other antidepressants that can lower sodium levels may also interact poorly, since licorice’s effect on electrolyte balance could worsen or mask symptoms of low sodium.
Diabetes Medications
Licorice can raise blood sugar levels, working against insulin and oral diabetes medications. If you’re carefully managing blood sugar with medication, regular licorice consumption may make your levels harder to control. Your readings may creep upward without an obvious dietary explanation, which could lead to unnecessary medication adjustments.
Laxatives
Stimulant laxatives, like many diuretics, can cause potassium loss through the gut. Using them alongside licorice compounds the potassium-depleting effect. People who use laxatives frequently and also consume licorice tea or supplements are at particular risk for dangerously low potassium without realizing the two are connected.
How Much Licorice Causes Problems
You don’t need to consume large quantities for interactions to occur. As little as 5 grams of licorice root per day (roughly one to two cups of licorice tea) over a few weeks can measurably lower potassium and raise blood pressure in some people. Sensitivity varies widely. Older adults and people with existing heart or kidney conditions tend to be more vulnerable at lower doses.
The effects are cumulative and can take weeks to build up, which makes the connection easy to miss. Symptoms like fatigue, muscle weakness, swelling, or rising blood pressure may develop gradually enough that neither you nor your doctor initially connects them to licorice consumption.
Deglycyrrhizinated licorice, often labeled as DGL, has had the glycyrrhizin removed and is generally considered safe with medications. If you want the digestive benefits of licorice without the drug interactions, DGL supplements are the standard workaround. Check the label carefully, though, because some products marketed as licorice supplements still contain the full compound.
What to Do if You Take These Medications
If you’re on any of the medications listed above, the safest approach is to avoid real licorice entirely or limit it to very occasional, small amounts. “Occasional” generally means not daily and not in supplement-strength doses. A single piece of real licorice candy once in a while is unlikely to cause a crisis, but daily licorice tea, regular use of licorice root supplements, or habitual chewing tobacco containing licorice can absolutely push you into dangerous territory.
If you’ve been consuming licorice regularly and take any of these medications, mention it next time you have bloodwork done. A basic metabolic panel will show your potassium level and give a clear picture of whether your electrolytes have shifted. Most licorice-related effects reverse within one to two weeks after stopping consumption, though potassium levels sometimes take longer to fully normalize.