Due to the relative high incidence of side effects of immunotherapy, particularly in those with a severe food allergy, several studies have been undertaken to determine if various adjuvants can be useful during immunotherapy regimes. These include the use of omalizumab, a monoclonal antibody directed against IgE which hinders allergen-specific IgE binding to IgE receptors and thus prevents the immediate consequences of allergen exposure. This has been used in a few clinical studies to speed up the oral immunotherapy process, the reduce the adverse effects and to increase the threshold at which an individual reacts to the allergen. The use of food immunotherapy in conjunction with omalizumab is an expanding area of research but further studies are required to determine the optimise the protocols for safety and efficacy, and to determine which patients would benefit most from this approach. Other adjuncts which have been studied during allergen immunotherapy include microbial products such as prebiotics and probiotics, and vitamin D.