Enjoy histamine rich foods and beverages again by utilizing GI Hist! 300mg of Porcine Kidney Extract = 20,000 IUs of Diamine Oxidase (DAO) G.I. Hist Support is a formula designed to assist patients who have trouble processing external sources of histamine rich foods and nutritional elements. This formula is especially helpful for those with genetic weaknesses in A01C (Diamine Oxidase), the main enzyme responsible for the degradation of ingested histamine.* A key active ingredient in G.I. Hist Support is porcine-derived diamine oxidase (DAO), and research suggests that DAO derived from porcine kidney appears to have identical action to DAO derived from porcine intestine. Along with 5 other ingredients shown to support allergy relief, GI Hist is one of the best supplements on the market that includes key cofactors along with high dose DAO.* Each ingredient is clinically tested to assist with histamine degradation and the oxidative stress created by histamines.*