Currently, there are two main types of allergy immunotherapy. They are allergy shots, which are the most common, and sublingual immunotherapy (also known as SLIT). Allergy shots involve injecting small doses of an allergen into the body so that it can become less sensitive to it over time. Allergy shots typically work well in those who have allergies to pet dander, pollen, dust, and insect bites, or who suffer from allergy-related asthma. Unfortunately, they don’t have as much success when it comes to treating food, medicine, or feather allergies. In comparison, sublingual immunotherapy treats certain allergies without injections. Instead, small doses of an allergen are placed under the tongue, exposing the body to a manageable amount of the substance. This is done repeatedly over time with the amount of allergen increasing throughout the treatment process. This periodic exposure improves tolerance to the substance and reduces symptoms.