Licorice Root: Forms, Traditional Uses and Glycyrrhizin Thresholds

An anise flavor doesn't prove the presence of root, and the absence of the word "licorice" on the front doesn't guarantee the absence of glycyrrhizin: the ingredient list may mention "glycyrrhizic acid" or "licorice extract."

Glycyrrhizin, or glycyrrhizic acid, has mineralocorticoid-like effects: sodium and water retention, potassium loss, and a rise in blood pressure. This mechanism is well established, far more so than the plant's therapeutic benefits.

The possible consequences of repeated exposure (high blood pressure, low potassium, heart rhythm disturbances) are detailed in our article on licorice, blood pressure and interactions.

The European Medicines Agency (EMA) monograph recognizes a traditional use of licorice root preparations to relieve certain digestive complaints, such as heartburn and dyspepsia, and as an expectorant for coughs linked to a cold. These uses come with defined preparations and durations.

This recognition rests on the long history of use. It doesn't demonstrate clinical effectiveness against reflux, ulcers, liver disease, fatigue, or immunity. A Cochrane review devoted to non-Chinese herbal medicines for functional dyspepsia judges the evidence insufficient.

No single figure suits every candy, drink, tea, and supplement, because glycyrrhizin concentration varies by plant, preparation, and product, and because sensitivity varies from person to person.

Several benchmarks exist nonetheless:

• The WHO/FAO expert committee (JECFA) has not set an acceptable daily intake. It estimates that an intake of 100 mg of glycyrrhizin per day is unlikely to cause effects in most adults, while acknowledging that sensitive individuals may react to less.
• In France, licorice-based food supplements must not, at the recommended daily dose, provide more than 100 mg of glycyrrhizin.
• In the European Union, a warning notice for people with high blood pressure is mandatory on candies exceeding 4 mg of glycyrrhizin per gram and on drinks exceeding 50 mg per liter (300 mg per liter for those containing more than 1.2% alcohol).

These benchmarks regulate products; they aren't meant to calculate a personal dose. Anses mainly recommends avoiding the stacking of sources: candies, anise-flavored drinks, syrups, teas, and supplements can add up without anyone noticing.

Deglycyrrhizinated licorice (DGL) sharply reduces glycyrrhizin content. According to the NCCIH, the U.S. agency for complementary medicine, oral products of this type appear safe for up to four months. Their composition and indication still need to be checked on the label.

Don't transpose data from a deglycyrrhizinated extract to a whole-root tea, nor data from a studied preparation to a supplement that doesn't specify its standardization.

The NCCIH judges consumption of about 250 g of licorice per week dangerous during pregnancy, and links large amounts of extract to a risk of delivery before 38 weeks. Data on breastfeeding are limited. Avoid medicinal licorice without advice during these periods.

Caution also applies to children and in the case of high blood pressure, heart, kidney, or liver disease, low potassium, a high-salt diet, or treatment affecting potassium.

• Look for the species and plant part used.
• Distinguish flavoring, root, tea, extract, and deglycyrrhizinated product.
• Look for the glycyrrhizin content, or the phrase "glycyrrhizin-free" where it applies.
• Check the amount per dose and the recommended duration.
• Be wary of claims about blood pressure, reflux, the liver, energy, or hormones.

The safest approach is to note every source consumed, its form, and its duration, then show it to a pharmacist or doctor. That's more reliable than an approximate conversion of grams of root into milligrams of glycyrrhizin.