What is Histamine Block derived from? Ceylon Keeslar March 28, 2018 21:29 Updated Follow Diamine Oxidase is derived from porcine (pig) protein concentrate. Vitamin C (ascorbic acid) is derived from non-GMO corn. Related articles What is the expiration date of Histamine Block? Does Histamine Block contain corn or grain-derived ingredients? What is the purpose of the "Other Ingredients" in the Histamine Block? Are there any side-effects or precautions when using Histamine Block? Is the shellac in Histamine Block dangerous? Comments 0 comments Article is closed for comments.