Allergen specific immunotherapy, comprised of subcutanoues injections of increasing doses of allergen extracts, has been shown to be the only treatment able to influence the natural progression of allergic disease. Different forms of local immunotherapies, involving oral, sublingual and nasal routes of allergen adminstration, have also been considered in clinical practice. The inability of the protein to survive gastrointestinal physiological barriers is a generally encountered problem in oral administration of protein drugs. In order to overcome the problems of low allergen bioavailability and absorptivity, during oral immunotherapy, several stabilization strategies have been outlined in the recent years. This review focuses on interventions including: hexose monosaccharide, ethyl alcohol and water vehicles, oxygen-containing metal salt based preparations, particles with enteric coating, and poly (lactic-co-glycolic) acid microspheres. Regarding the enormous potential of oral responsiveness and/or oral tolerance, research that focuses on new and improved carriers or vehicles for safe allergen oral delivery has great potential in treating allergic diseases. This article also review some of the recent patent related to the field.