Licorice and Medications: Unexpected Interactions with a Common Candy

Most people think of licorice as a sweet, chewy candy-something you grab for a quick treat or maybe use to soothe a sore throat. But what if that candy is quietly messing with your blood pressure, your potassium levels, or even the meds you take every day? It’s not a myth. Licorice isn’t just flavor. It’s a powerful plant with real, measurable effects on your body-and it’s hiding in plain sight.

What’s Really in Your Licorice?

Not all licorice is the same. The kind that causes problems contains glycyrrhizin, a compound from the root of the Glycyrrhiza glabra plant. This is what gives traditional black licorice its deep, earthy taste. But here’s the catch: many candies labeled as "licorice"-especially in the U.S.-are actually flavored with anise oil. No glycyrrhizin. No risk. You’re just eating a sweet that smells like licorice.

Real licorice? That’s the dangerous kind. A single 50-gram bag of traditional black licorice candy can contain up to 100 mg of glycyrrhizin. That’s the daily limit set by the European Food Safety Authority for healthy adults. Eat two bags a day for a few weeks? You’re in trouble.

Herbal supplements are even worse. Some licorice extracts contain up to 24% glycyrrhizin. That means a single capsule could pack the same punch as half a bag of candy. And most labels? They don’t tell you how much is in there. A 2023 Consumer Reports survey found that 78% of black licorice products didn’t list glycyrrhizin content at all.

How Licorice Changes Your Body

Glycyrrhizin doesn’t just taste strong-it acts like a hormone. It blocks an enzyme called 11β-HSD2, which normally protects your body from too much cortisol. When that enzyme is blocked, cortisol starts behaving like aldosterone-a hormone that tells your kidneys to hold onto salt and flush out potassium.

The result? Your body retains water. You gain weight. Your blood pressure spikes. And your potassium drops. That’s not just inconvenient. It’s dangerous.

Low potassium can cause muscle cramps, fatigue, and irregular heartbeats. In extreme cases, it leads to cardiac arrest. One 2012 case study described a 47-year-old man who ate 200 grams of licorice daily for three weeks. His potassium plummeted to 2.6 mmol/L (normal is 3.5-5.0). His blood pressure hit 210/120. He ended up in the hospital.

Another case? A woman on fludrocortisone-a steroid that already raises blood pressure-developed panic attacks and a systolic pressure of 205 after eating licorice. Her doctor had no idea the candy was the trigger.

When Licorice Meets Your Meds

This is where it gets real. Licorice doesn’t just affect your body. It interferes with medications you’re already taking.

• Diuretics (water pills): If you’re on hydrochlorothiazide or furosemide, your body is already losing potassium. Licorice makes it worse. One study showed patients dropping below 3.0 mmol/L-dangerously low.
• High blood pressure meds: Licorice fights against ACE inhibitors like lisinopril and ARBs. People on these drugs have reported sudden spikes in blood pressure after eating licorice. One Reddit user went from 120/80 to 165/95 in three days.
• Warfarin and other blood thinners: Licorice can either increase or decrease the effect of warfarin. One case showed a patient’s INR (a measure of blood clotting) suddenly dropping after licorice use. Another showed dangerous bleeding. It’s unpredictable.
• Digoxin: Used for heart rhythm issues. Licorice-induced low potassium makes digoxin toxic-even at normal doses. A 2002 case report described a patient with digoxin poisoning after eating licorice, with potassium at 2.8 mmol/L.
• Corticosteroids: Fludrocortisone, prednisone, dexamethasone-these already mimic aldosterone. Add licorice? Your body gets flooded with mineralocorticoid effects. Swelling, high BP, low potassium. It’s a perfect storm.

And it’s not just about what’s in the bottle. Licorice can also interfere with how your liver breaks down drugs. Some compounds in licorice inhibit CYP3A4 and CYP2D6 enzymes-key players in metabolizing everything from statins to antidepressants. Others induce them. The net effect? It depends on the licorice product, your genes, and what else you’re taking. That’s why some people get hit hard, while others seem fine.

DGL: The "Safe" Version?

You might see "DGL" on a supplement bottle-Deglycyrrhizinated Licorice. That means most of the glycyrrhizin has been removed. This version is often marketed for stomach ulcers or heartburn. And yes, it’s much safer. DGL contains less than 1% glycyrrhizin. You can take it without worrying about blood pressure or potassium.

But here’s the problem: most people don’t know the difference. They see "licorice root extract" and assume it’s the same as the candy they ate as a kid. Labels rarely clarify. If you’re on meds, always check the label for glycyrrhizin content-or better yet, ask your pharmacist.

Who’s at Risk?

It’s not just the elderly or the chronically ill. Anyone taking these meds is vulnerable:

• People with high blood pressure or heart disease
• Those on diuretics, steroids, or heart meds
• Older adults (over 60), whose kidneys are less efficient at handling potassium
• People with kidney disease or liver problems
• Anyone consuming more than 100 mg of glycyrrhizin per day for over two weeks

And here’s the kicker: symptoms can be subtle. Fatigue. Headaches. Swollen ankles. A sudden need to pee more. These aren’t red flags-until they are. One patient developed carpal tunnel syndrome from fluid retention caused by licorice. Another had a stroke from a blood clot linked to low potassium.

What Should You Do?

If you take any of these medications, here’s what matters:

1. Check your candy. If it’s dark, chewy, and tastes like licorice root-not anise-it likely contains glycyrrhizin. Look for "real licorice" on the label. If it’s not there, assume it’s anise.
2. Read supplement labels. Avoid anything listing "licorice root extract" unless it says "DGL" or "deglycyrrhizinated."
3. Don’t eat more than 50g of black licorice per week. Even that’s pushing it if you’re on meds. Better yet: avoid it entirely.
4. Ask your pharmacist. Only 37% of community pharmacists in one study could correctly identify all licorice-drug interactions. Don’t assume they know. Bring the label.
5. Monitor your body. If you’ve eaten licorice and notice swelling, muscle weakness, or a headache that won’t go away, get your blood pressure and potassium checked.

There’s no official FDA limit for licorice, but the European standard of 100 mg glycyrrhizin per day is the best benchmark we have. That’s about one small bag of candy. Two bags? You’re in the danger zone.

The Bigger Picture

The licorice market is growing-worth over $1.3 billion in 2022. Supplements make up a third of that. But regulation? It’s lagging. The UK requires warning labels on high-glycyrrhizin products. Japan limits supplements to 100 mg/day. The FDA? Still says licorice is "Generally Recognized As Safe." But their own adverse event database recorded 147 cases of licorice-related harm between 2010 and 2020. Nearly half involved high blood pressure. Almost a third involved dangerously low potassium.

By 2026, the American Herbal Pharmacopoeia wants all licorice products to list glycyrrhizin content on the label. That’s a step forward. But until then, you’re on your own.

Licorice isn’t evil. It’s not poison. But it’s not harmless, either. It’s a plant with powerful chemistry. And if you’re taking medication, that chemistry can turn a sweet treat into a silent threat.

What to Do Next

If you’ve been eating licorice and are on medication, don’t panic. But do act. Check your pantry. Read supplement labels. Look for "glycyrrhizin" or "licorice root extract." If you find it, stop. Talk to your doctor or pharmacist. Get a simple blood test to check your potassium and blood pressure. It takes five minutes. It could save your life.

Licorice isn’t the enemy. But ignorance is. The next time you reach for that black stick, ask yourself: is this candy-or a hidden drug interaction?