What’s in Licorice? | The Ingredient That Raises Pressure

Licorice root contains glycyrrhizin, a sweet compound that can raise blood pressure and deplete potassium when eaten regularly.

When you bite into a piece of black licorice, you’re not just eating candy. You’re consuming a root extract that contains a compound powerful enough to affect your blood pressure, alter your electrolyte balance, and in rare cases send someone to the hospital. That’s not an exaggeration — it’s a well-documented effect that has caught the attention of cardiologists and public health organizations worldwide.

So what exactly is in licorice that makes it so different from other sweets? This article covers the key compounds found in licorice root, how they affect your body, and what the research says about safe consumption. If you enjoy black licorice candy, tea, or supplements, this breakdown will help you understand what you’re taking in and when it might matter.

What’s Actually in Licorice Root?

Licorice root comes from the plant Glycyrrhiza glabra, which has been used for centuries as both a sweetener and an herbal remedy. The root contains several bioactive compounds, with the most well-studied being glycyrrhizin — also called glycyrrhizic acid. This compound is responsible for licorice’s intense sweetness and most of its physiological effects.

Other compounds found in licorice root include glabridin and isoliquiritigenin, which have been studied for potential applications in oral health. But when most people ask what’s in licorice that matters for their health, the answer is glycyrrhizin. It’s the component that can cause sodium retention, potassium loss, fluid buildup, and higher blood pressure.

The amount of glycyrrhizin in licorice products varies widely. Black licorice candy, licorice tea, and licorice extract supplements all contain different concentrations. Even within candy brands, the glycyrrhizin content can differ depending on how much extract is used in the recipe.

Why Glycyrrhizin Raises Health Concerns

The reason licorice gets attention from cardiologists comes down to how glycyrrhizin interacts with your body’s fluid regulation system. It interferes with the renin-aldosterone axis, which normally controls how much sodium you retain and how much potassium you excrete. Here’s what happens when that balance gets disrupted.

• Sodium retention: Glycyrrhizin causes the kidneys to hold onto more sodium, which increases blood volume and raises blood pressure.
• Potassium loss: The same mechanism triggers potassium excretion, which can drop levels low enough to cause muscle cramps, fatigue, or heart rhythm changes.
• Fluid buildup: Retaining sodium pulls water into your bloodstream and tissues, which can lead to swelling in your legs, feet, or hands.
• Blood pressure rise: A 2024 meta-analysis found that glycyrrhizic acid significantly increases both systolic and diastolic blood pressure across multiple studies.
• Hormone mimicry: Glycyrrhizin structurally resembles aldosterone, the hormone that naturally regulates salt and water balance, which is how it interferes with normal kidney function.

The effects are dose-dependent, meaning more licorice leads to more pronounced changes. But a 2024 Swedish study found that even small amounts can cause blood pressure to rise, which is why major health organizations advise caution.

How Much Licorice Is Considered Safe?

The World Health Organization has suggested that 100 mg of glycyrrhizic acid per day is a tolerable intake level. That amount corresponds to roughly 2 to 3 ounces of black licorice candy for most products, though concentrations vary by brand. Because manufacturers don’t always list glycyrrhizin content on labels, it’s difficult to give a universal number that applies to everything on the shelf.

What the Research Shows

A guide hosted by Rutgers University examined the licorice potassium depletion and swelling risks in detail, noting that glycyrrhizic acid can cause significant electrolyte disturbances at regular intake levels. The university’s warning echoes findings from the American Heart Association, which advises caution with black licorice because ingredients vary by brand.

The challenge is that individual sensitivity varies considerably. Some people experience blood pressure changes after a single serving, while others tolerate regular consumption with minimal effects. Age, kidney function, and existing medical conditions all influence how your body handles glycyrrhizin. The 2024 Swedish study confirmed that even low daily doses affect renin, aldosterone, and blood pressure, suggesting there’s no truly risk-free level for everyone.

Who Should Be Cautious About Licorice?

The British Heart Foundation advises that it’s sensible for certain groups to limit or avoid licorice products. Because glycyrrhizin affects blood pressure and electrolyte balance, people with specific health conditions face higher risks. Here are the groups that should be most careful.

1. People with high blood pressure: Even small amounts of licorice can raise blood pressure further, making it harder to manage with medication or lifestyle changes.
2. Those with cardiovascular disease: Fluid retention and electrolyte shifts from glycyrrhizin add extra strain on the heart and circulatory system.
3. Anyone taking diuretics or heart medications: Potassium-wasting diuretics combined with licorice can worsen potassium depletion, and some heart medications interact with electrolyte shifts.
4. People with kidney disease: Impaired potassium regulation makes the effects of glycyrrhizin more dangerous, since the kidneys can’t compensate as effectively.
5. Older adults: Age-related changes in kidney function and blood pressure regulation increase vulnerability to licorice’s effects.

Even people without these conditions may see their blood pressure rise with regular licorice consumption. The British Heart Foundation notes that licorice sweets and tea can pose risks for anyone who consumes them frequently.

What About Licorice Candy and Supplements?

Most black licorice candy uses wheat flour as a base, along with sugar, molasses, and licorice extract. The American Heart Association notes that ingredients vary by brand, so glycyrrhizin content can differ significantly between products. One popular variety pack has 140 calories and 17 grams of sugar per 40-gram serving. Red licorice typically contains no actual licorice — it’s usually strawberry- or cherry-flavored candy.

Licorice is also used as a flavoring in tobacco, beverages, and some pharmaceuticals, and is sold as a dietary supplement. Even low daily doses affect renin, aldosterone, and blood pressure, according to a 2024 glycyrrhizic acid blood pressure study. This means even moderate consumption can have measurable effects on your cardiovascular system.

Is There a Safer Alternative?

For those who want the flavor without the side effects, deglycyrrhizinated licorice (DGL) is available. DGL has the glycyrrhizin removed, so it doesn’t affect blood pressure or potassium. It’s sometimes used in supplements aimed at digestive health, though evidence for those uses is limited.

The Bottom Line

Licorice is a unique food because it’s both a candy and a source of a bioactive compound with measurable effects on the body. Glycyrrhizin can raise blood pressure, deplete potassium, and cause fluid retention — effects that are well-documented by multiple studies and health organizations. If you have high blood pressure, heart disease, or kidney concerns, limiting or avoiding licorice products is a sensible precaution.

If you regularly enjoy black licorice and have any cardiovascular concerns, a conversation with your doctor or pharmacist can clarify whether it fits safely with your medications and overall health profile.