Histamine Digest delivers DAO directly to your small intestine to replenish your supply and to resolve the histamine intolerance triggered by the histamine-rich foods you eat. Histamine Digest is indicated for those with intolerance to dietary histamine and occasional digestive distress related to histamine-containing foods and beverages and delivers naturally derived diamine oxidase to the small intestine, where it acts directly on dietary histamine to help defend against histamine-related reactions and digestive discomfort. Unlike pharmaceutical solutions, DAO supplementation combats not only your allergy-like symptoms but the root cause behind them: your deactivated DAO enzyme.