Black Licorice Benefits: What Research Shows About This Ancient Herb
Black licorice isn't just a candy flavor. The root it comes from — Glycyrrhiza glabra, commonly called licorice root — has been used in traditional medicine across Asia, the Middle East, and Europe for thousands of years. Modern nutrition science has begun examining some of those traditional uses, with results that are genuinely interesting but also worth understanding carefully.
What Makes Licorice Root Distinctive
The primary active compound in licorice root is glycyrrhizin (also called glycyrrhizic acid), a saponin that gives licorice its characteristic intensely sweet taste — roughly 30 to 50 times sweeter than table sugar. Glycyrrhizin is metabolized in the body into glycyrrhetinic acid, which is the form that produces most of licorice root's documented physiological effects.
Licorice root also contains flavonoids — including liquiritin, isoliquiritigenin, and glabridin — which have attracted attention for their antioxidant properties in laboratory and early clinical research. These flavonoids are structurally distinct from glycyrrhizin and may have separate mechanisms of action.
What the Research Generally Shows
Anti-Inflammatory Properties 🌿
Several laboratory and early clinical studies have looked at licorice root's anti-inflammatory potential, particularly related to glycyrrhetinic acid's ability to inhibit certain enzymes involved in the inflammatory response — specifically 11β-hydroxysteroid dehydrogenase and phospholipase A2. This enzyme-inhibiting activity is a plausible mechanism, though most research remains in early stages, with stronger evidence from in vitro (cell-based) and animal studies than from large-scale human clinical trials.
Digestive Health Research
Some of the more consistently studied areas involve digestive support. Research on deglycyrrhizinated licorice (DGL) — a processed form with most of the glycyrrhizin removed — has explored its role in supporting the mucosal lining of the stomach and esophagus. A handful of clinical studies suggest DGL may be relevant to managing discomfort associated with acid reflux and ulcers, though findings are mixed and study sizes tend to be small.
Respiratory and Throat Use
Traditional use of licorice root as a soothing agent for coughs and sore throats has some basis in its demulcent properties — meaning it may coat and soothe irritated mucous membranes. This is a well-recognized category of herbal action, though rigorous clinical trial evidence specifically for licorice root in this role remains limited.
Antimicrobial and Antiviral Research
Glycyrrhizin has been studied in laboratory settings for activity against several viruses and bacteria. Some early research looked at its effects on viral replication mechanisms in vitro. These findings are preliminary, and laboratory results do not automatically translate into clinical effectiveness in humans.
Skin-Related Research
Glabridin, one of the flavonoids in licorice root, has been examined for its ability to inhibit tyrosinase, an enzyme involved in melanin production. This has generated interest in licorice extract as an ingredient in skin-lightening and hyperpigmentation research, and it's among the more active areas of ongoing study. Again, most evidence is from laboratory or small-scale studies.
A Critical Distinction: Real Licorice vs. Licorice-Flavored Products
Most commercially sold black licorice candy in the United States does not contain actual licorice root. It's typically flavored with anise oil, which produces a similar taste. Only products explicitly labeled as containing licorice root extract or glycyrrhizin have the compounds discussed above.
This distinction matters significantly when evaluating both the potential benefits and the risks.
The Variables That Shape Individual Outcomes
| Factor | Why It Matters |
|---|---|
| Form (whole root, extract, DGL, candy) | Glycyrrhizin content varies dramatically across forms |
| Dosage and duration | Risks associated with glycyrrhizin are dose- and time-dependent |
| Age | Older adults may be more sensitive to glycyrrhizin's effects on blood pressure |
| Existing cardiovascular health | Those with hypertension face greater risk from regular glycyrrhizin intake |
| Kidney and liver function | Affects how glycyrrhizin is processed and cleared |
| Medications | Notable interactions with corticosteroids, diuretics, digoxin, and blood pressure medications |
| Pregnancy status | Research suggests licorice root should be avoided during pregnancy |
The Risks Deserve Equal Attention ⚠️
Glycyrrhizin's mechanism — particularly its effect on cortisol metabolism — can cause the body to retain sodium and excrete potassium. In sufficient quantities, this leads to a condition called pseudohyperaldosteronism, which can raise blood pressure, cause fluid retention, and lead to low potassium levels (hypokalemia). The FDA has published guidance noting that eating large amounts of black licorice (containing real glycyrrhizin) regularly — even for a couple of weeks — can cause heart rhythm problems, particularly in people over 40.
This is not a theoretical risk. It is documented in case reports and represents one of the more concrete examples of a "natural" food or herb producing clinically significant adverse effects at high intake.
DGL supplements are designed to reduce this concern by removing most of the glycyrrhizin, but the specific glycyrrhizin content of any product is rarely standardized in a way consumers can easily verify.
How Individual Health Profiles Change the Picture
For someone in good general health with no cardiovascular concerns who occasionally consumes small amounts of real black licorice, the exposure to glycyrrhizin may be modest enough that no significant effect is likely. For someone managing high blood pressure, taking certain heart medications, or who is pregnant, even moderate consumption represents a meaningfully different risk profile.
The flavonoids in licorice root — glabridin and related compounds — don't carry the same cardiovascular concerns as glycyrrhizin, which is part of why research on licorice extracts standardized for specific flavonoids (rather than glycyrrhizin) is a separate and growing area of inquiry.
Whether the research on licorice root's anti-inflammatory, digestive, or skin-related properties is relevant to any particular person depends on their health status, what medications they take, what form of licorice they're considering, how much, and for how long — and those are the variables this page cannot weigh for you.
