Black licorice has real health benefits, but it also carries real risks that most people don’t expect from a candy or herbal tea. The active compound in licorice root, glycyrrhizic acid, has genuine anti-inflammatory and digestive properties. It also raises blood pressure and depletes potassium. Whether black licorice is “good for you” depends entirely on how much you eat, how often, and your individual health profile.
What Makes Black Licorice Biologically Active
Real black licorice comes from the root of the licorice plant and contains glycyrrhizic acid, typically making up 1% to 12% of the product by weight. This compound is responsible for both the health benefits and the health risks. It reduces inflammation by dialing down several of the body’s key inflammatory signaling pathways, including ones involved in immune cell activation and the production of pain and swelling signals. It also blocks an enzyme that normally converts cortisol (your body’s stress hormone) into an inactive form. The result is that more cortisol stays active in your body, which can be helpful in small doses but harmful in large ones.
Not all “licorice” candy actually contains licorice. Many products, especially red licorice, are flavored with anise oil and contain none of the active compound. If the ingredient list doesn’t include licorice root extract or glycyrrhizic acid, the health effects described here don’t apply.
Digestive and Stomach Benefits
Licorice root has the strongest evidence for digestive health. It protects the stomach lining through several mechanisms: it reduces stomach acid secretion, boosts the production of protective mucus, stabilizes the cells lining the stomach wall, and promotes the synthesis of compounds that help maintain that lining. Licorice extract also prevents Helicobacter pylori, the bacterium responsible for most stomach ulcers, from attaching to the stomach wall in the first place.
That said, the clinical evidence is more modest than the laboratory science might suggest. A systematic review pooling data from multiple studies found that licorice showed a trend toward improved ulcer symptoms and healing compared to placebo, but the results did not reach statistical significance. So while licorice likely offers some stomach-protective effects, it’s not a proven replacement for standard ulcer treatments.
Cough and Sore Throat Relief
Licorice has been used for centuries in traditional medicine for coughs, sore throats, asthma, and bronchitis. Modern research supports this to a degree. Specific compounds in licorice reduced cough frequency by 30% to 78% in animal models and showed significant expectorant activity, helping to loosen and move mucus out of the airways. These effects work through both the throat and airway nerves (peripheral) and the brain’s cough center (central). Licorice root tea for a sore throat isn’t just folk wisdom; there’s a plausible biological basis for the relief people report.
The Potassium and Blood Pressure Problem
Here’s where black licorice gets dangerous. By blocking the enzyme that deactivates cortisol, glycyrrhizic acid causes your body to behave as though it’s producing too much aldosterone, the hormone that regulates salt and water balance. The result is sodium retention, potassium loss, fluid buildup, and elevated blood pressure. In a clinical study of 18 healthy volunteers, just 225 mg per day of glycyrrhizic acid suppressed the body’s normal blood pressure regulation system and caused measurable potassium depletion.
The FDA warns that if you’re 40 or older, eating 2 ounces of black licorice daily for at least two weeks could put you in the hospital with an irregular heart rhythm. This isn’t theoretical. Case reports document severe, life-threatening arrhythmias caused by licorice-induced potassium depletion. In one published case, an 89-year-old woman required more than 30 defibrillation shocks over 10 hours after her potassium dropped to dangerous levels from licorice consumption.
People with heart disease, kidney disease, or high blood pressure are especially sensitive. Eating 5 grams or more of glycyrrhizic acid-containing licorice daily for several weeks can cause severe side effects including heart attack.
Risks During Pregnancy
Pregnant women face a distinct set of risks. Glycyrrhizic acid crosses the placenta and disables the enzyme that normally shields the fetus from the mother’s higher cortisol levels. A study published in the American Journal of Epidemiology tracked children whose mothers consumed high amounts of licorice during pregnancy (500 mg or more of glycyrrhizic acid per week). Compared to children with minimal exposure, the high-exposure group showed measurable drops in verbal ability, spatial reasoning, and memory, with scores falling roughly a third of a standard deviation lower. They also had two to three times the odds of clinically significant attention problems, aggression, and rule-breaking behavior. High maternal consumption was also linked to slightly shorter pregnancies, about 2.4 days on average.
How Much Is Safe
The World Health Organization reviewed the available data and concluded that an intake of 100 mg per day of glycyrrhizic acid (roughly 2 mg per kilogram of body weight) would be unlikely to cause adverse effects in most adults. To put that in practical terms, a single piece of black licorice candy might contain anywhere from 5 to 50 mg of glycyrrhizic acid depending on the brand and concentration, so occasional snacking is generally fine. The problems arise with daily, sustained consumption over weeks.
The FDA doesn’t set a hard limit but “encourages moderation,” with its two-ounce, two-week warning as a practical guardrail. If you enjoy black licorice, eating it occasionally rather than habitually is the simplest way to stay safe.
DGL: The Lower-Risk Alternative
If you want the digestive benefits of licorice without the cardiovascular risks, deglycyrrhizinated licorice (DGL) is the standard workaround. DGL is licorice root with the glycyrrhizic acid removed, eliminating the compound responsible for potassium loss and blood pressure spikes. DGL supplements in doses up to 4.5 grams daily have been used for up to four months without the side effects associated with regular licorice. DGL retains many of the stomach-protective properties of whole licorice root, making it a reasonable option for people dealing with indigestion or mild stomach irritation who want to avoid risk.
DGL is widely available as chewable tablets and capsules, often marketed specifically for digestive support. It won’t give you the anti-inflammatory or cough-suppressing effects that depend on glycyrrhizic acid, but for gut health specifically, it covers most of the benefit with very little downside.