An herbal medicine. Licorice root is used to treat viral infections, including colds, AIDS (acquired immunodeficiency syndrome], and hepatitis; inflammation; menstrual and menopausal disorders; peptic ulcers; canker sores; herpes; eczema; and psoriasis. Licorice root has many possible medicinal actions, including antiallergic, antiviral, anti-inflammatory, and hormonal actions. Its major active component is glycyrrhizin. It should not be used at high doses or for a prolonged time because it can be toxic.