There are two types of licorice, “standard” licorice and “de-glycyrrhizinated” licorice (DGL). Each type is suitable for different conditions. The standard licorice containing glycyrrhizin should be used for respiratory infections, chronic fatigue syndrome or herpes (topical). Licorice root in capsules, 5–6 grams per day, can be used. Concentrated extracts, 250–500 mg three times per day, are another option. Alternatively, a tea can be made by boiling 1/2 ounce (14 grams) of root in 1 pint (500 ml) of water for fifteen minutes, then drinking two to three cups (500–750 ml) per day. Long-term internal use (more than two to three weeks) of high amounts (over 10 grams per day) of glycyrrhizin-containing products should be attempted only under the supervision of a doctor. Licorice creams or gels can be applied directly to herpes sores three to four times per day.

DGL is prepared without the glycyrrhizin in order to circumvent potential safety problems (see below), and is used for conditions of the digestive tract, such as ulcers. For best results, one 200–300 mg tablet is chewed three times per day before meals and before bed.⁹ For canker sores, 200 mg of DGL powder can be mixed with 200 ml warm water, swished in the mouth for three minutes, and then expelled. This may be repeated three or four times per day.