Glycyrrhiza glabra; Glycyrrhiza inflata; Glycyrrhiza uralensis

The root of this leguminous herb is used. It contains essential oil, coumarins, flavonoids, terpenoids (glycyrrhizin) and phytoestrogens. Attributed properties: anti-ulcer and expectorant. Indication Commission E German Ministry of Health ^{(Blumenthal 1998)}: gastritis, ulcers, cough, bronchitis. Glycyrrhizin is a powerful sweetener used in the food industry.

Glycyrrhizin, responsible for many of the effects of liquorice, is excreted in small amounts in breast milk. ^{(Shimada 1994)}

Two infants under one month of age were severely intoxicated (lethargy) after their mothers drank an average of two litres per day of an infusion mixture of liquorice, fennel, aniseed and galega. The effect was attributed to the anethole in aniseed and fennel. ^{(Rosti 1994)}

Abuse or prolonged use of liquorice can cause serious health problems due to its mineralocorticoid effects: pseudoaldosteronism, hypokalaemic paralysis, hypernatraemia, oedema, cardiac arrhythmias and high blood pressure. ^{(Robles 2013, Panduranga 2013, Oztürk 2013, Omar 2012, Cuzzolin 2006, Werner 1979)}

When taken during pregnancy, it can cause miscarriage and premature birth. ^{(Strandberg 2002)}

It has oestrogenic ^{(Powers 2015, Zava 1998)} and antiprolactin effects, so it could decrease milk production during the first weeks of the postpartum period. ^{(Le Moli 1999)}

A case of hyperprolactinemia associated with chronic consumption of liquorice has been published ^{(Werner 1979)}, and although it is used in some cultures to increase milk production ^{(Chao 2021)}, there is no evidence of its effect as a galactagogue. In fact, it has oestrogenic ^{(Powers 2015, Zava 1998)} and antiprolactin effects ^{(Yuan 2008, Le Moli 1999)}, so it could decrease milk production during the first weeks of the postpartum period. An infusion, a mixture of liquorice and other herbs, did not cause an increase in maternal prolactin or weight in infants whose mothers took it. ^{(Sharma 1996)}

It should not be consumed during breastfeeding. ^{(Amir 2011, WHO 2010 & 1999)}