Sublingual Immunotherapy (SLIT), commonly known as allergy drops, offers an alternative treatment for managing environmental allergies without the need for injections. Unlike medications such as antihistamines, which provide immediate but temporary relief by masking symptoms, SLIT addresses the root cause of the allergic reaction. This therapy involves placing a small dose of allergen extract under the tongue daily to modify the immune system’s response. Because allergy drops work by retraining the body’s defenses, the process is gradual and requires patience.
The Science Behind Allergy Drops
Sublingual Immunotherapy works by exposing the immune system to small, regular amounts of the specific allergen that triggers a reaction. This process is called desensitization, and it slowly encourages the immune system to build tolerance to the substance. Placing the drops under the tongue allows the allergen to be absorbed by specialized immune cells in the oral mucosa. The goal is to shift the immune response from an allergic reaction, which is driven by Immunoglobulin E (IgE) antibodies, to a protective one. This protective response is characterized by the production of “blocking antibodies,” primarily Immunoglobulin G (IgG), which intercept the allergen before it can trigger the allergic cascade.
When Patients Notice Early Changes
The first signs that allergy drops are starting to work typically appear within three to six months of consistent daily treatment. This initial relief is often characterized by less severe symptoms or a reduced need to rely on rescue medications like antihistamines and nasal sprays. The exact timing of this early symptomatic relief can vary significantly among individuals. Factors such as the severity of the initial allergies, the specific allergens being treated, and strict adherence to the daily dosing schedule all influence the timeline. This early phase marks the body’s initial adjustment, where oral tolerance is beginning to build, but it is not the full, lasting immune change.
Reaching Full Treatment Effectiveness
Achieving the maximum therapeutic benefit from allergy drops, often referred to as reaching the maintenance phase, is a longer process. True immune tolerance typically takes six months up to one year of continuous daily therapy. During this extended period, the dosage of the allergen is gradually increased until the highest effective dose, known as the maintenance dose, is reached and sustained. This is when the long-term immune system changes become fully established, leading to a significant and sustained reduction in symptoms. Inconsistent dosing or skipping drops can disrupt this process, potentially delaying the achievement of peak effectiveness.
How Long Treatment Must Continue
To ensure the immune tolerance achieved is durable and long-lasting, the treatment protocol requires a significant commitment beyond the point of feeling better. Most allergists recommend that patients continue taking the daily allergy drops for a total duration of three to five years. This extended period is necessary for the immune system to solidify the new, tolerant state and “remember” it even after the drops are stopped. Stopping treatment prematurely risks losing the established tolerance, which can result in the allergy symptoms eventually returning. After completing the full course, the benefits of the therapy often persist for many years, sometimes for a decade or longer, providing sustained relief from allergic rhinitis and other symptoms.