Oral immunotherapy (OIT) is a preventative measure against food allergies that introduces increasing doses of an allergen to a patient under medical supervision. Research has sought to understand the benefits of introducing allergens in different age groups, but studies have yet to be compared to find the ideal window of time for children to be introduced to allergens. This literature review aims to determine whether this window exists in early childhood or the fetal stages to prevent the development of allergies using OIT.