Deglycyrrhizinated Licorice, also known as De-glycyrrhizinated licorice, or commonly referred to by the acronym DGL, is typically used as an herbal supplement in the treatment of gastric and duodenal ulcers. It is made from licorice from which the glycyrrhizin has been removed
The usual dosage is 760 mg, chewed, 20 minutes before a meal. Studies of DGL in humans and animals against placebos showed that DGL significantly reduced the size of gastric ulcers and hastened healing, with 44% of the subjects obtaining complete healing, as opposed to 6% of the control group. DGL has also been found to be an effective treatment for duodenal ulcers. In another study a group of 40 patients who had duodenal ulcers for 4–12 years were treated with 3 grams of DGL a day for 8 weeks, or 4.5 grams a day for 12 weeks, with all subjects showing vast improvement, with the higher dosage being the most significant. An additional study shows that DGL's therapeutic effect is equal to the effect of cimetidine. There have been no known cases of overdose, and very little reported side effects (nausea and diarrhea sometimes reported).
There are no known drug interactions with drugs used to treat ulcers. In Europe, South Africa, and Canada, DGL is marketed in a medicinal preparation called Caved-S. In the U.S., DGL is marketed as a herbal supplement.