The Alcat Test is now considered the, “gold standard” laboratory method for identification of non-IgE mediated reactions to over 400 different foods, chemicals, and other categories of substances. It is a functional response test and captures the final common pathway of many of the pathogenic mechanisms, immunologic, toxic, and pharmacologic that underlie non-IgE mediated reactions to foods and chemicals. Alcat Test frequently reveals clinically significant reactions that don’t fall within the conventional definition of allergy. The term “allergy” is often used as a catchall phrase to describe all of the body’s altered and excessive responses to otherwise harmless substances. However, a true allergic reaction is a function of the specific immune system while the broader category of intolerance is generally associated with nonspecific immunity. Food intolerance is much more common than true food allergy. However, many people are unaware that they suffer from food intolerance because their symptoms may vary widely and often appear hours, or even days, after the causative agent is consumed. Alcat Testing is based on the understanding that food intolerances arise from activation of cellular responses of the innate immune system. Instead of perceiving them as harmless, the immune system responds to specific foods and other substances as though they were threats requiring aggressive targeting, which, in fact, they may be.