It is recommended that, unless otherwise prescribed, an average daily dose of crude plant material, 5-15 g, or dry extracts corresponding to 200-800 mg of glycyrrhizin may be used. If taken as an infusion or decoction, 2-4 g in 150 ml water should be taken after meals thrice daily. Doses of other preparations should be calculated accordingly. Generally, licorice should not be used for longer than 4-6 weeks without medical advice. However, there is no objection to using licorice root as a flavoring agent up to a maximum daily dosage equivalent to 100 mg glycyrrhizin. Licorice is not recommended for use during pregnancy.
Prolonged use of excessive doses of licorice of more than 20 g/day for more than 6 weeks can lead to pseudoaldosteronism (excessive levels of aldesterone, a hormone produced by the adrenal cortex), potassium depletion, sodium retention, cardiovascular toxicity, water retention, edema, hypertension, headache, lethargy and weight gain.