The purpose of sublingual immunotherapy (SLIT/allergy drops) is to decrease your sensitivity to allergy-causing substances so that exposure to the offending allergen (pollen, mold, mites, animal dander, etc.) will result in fewer and less severe symptoms. This does not mean that sublingual immunotherapy is a substitute for the avoidance of known allergens or for the use of allergy medications but rather is a supplement to those treatment measures.
Sublingual immunotherapy has been shown to lead to an alteration of your immune system's response to naturally occurring allergens. These alterations may permit you to tolerate exposure to the allergen with fewer symptoms. You, in effect, become "immune" to the allergen. The amount of this immunization is indifferent to each person and is, therefore, somewhat unpredictable. This is a more convenient alternative to allergy shots. Allergy drops do not require weekly visits to our clinic.
Improvement in your symptoms will not be immediate. It usually requires 3 to 6 months before any relief of allergy symptoms is noted, and it may take 12-24 months for full benefits to be evident. About 85-90% of allergic patients on immunotherapy showed more significant improvement in their symptoms. This means that symptoms are reduced, although not always completely eliminated.