Advanced Orthomolecular Research DGL is deglycerrhizinated licorice, a supplement that supports a healthy digestive system and relieves the symptoms of ulcers. Ulcers occur because of a loss of the integrity of the intestinal lining. Most drugs that are used to treat ulcers do not address this underlying cause, and some are associated with negative side effects. DGL works by stimulating defense mechanisms to prevent ulcer formation, rather than simply inhibiting the release of stomach acid.